Oxide mixture and complex oxide coatings for cathode materials

ABSTRACT

Cathode active materials are provided. The cathode active material can include a plurality of cathode active compound particles. A coating is disposed over each of the cathode active compound particles. The coating can include at least one of ZrO2, La2O3, a mixture of Al2O3 and ZrO2 or a mixture of Al2O3 and La2O3. The battery cells that include the cathode active material are also provided.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This patent application claims the benefit under 35 U.S.C. § 119(e) ofU.S. Patent Application Ser. No. 62/713,715, entitled “OXIDE MIXTURE ANDCOMPLEX OXIDE COATINGS FOR CATHODE MATERIALS,” filed on Aug. 2, 2018,which is incorporated herein by reference in its entirety.

U.S. GOVERNMENT LICENSE RIGHTS

This invention was made with U.S. government support under NVFO ProposalNo. 85F59. This invention was made under a CRADA 1500801 between AppleInc. and Argonne National Laboratory operated for the United StatesDepartment of Energy. The U.S. government has certain rights in theinvention.

FIELD

This disclosure relates generally to batteries, and more particularly tocathode active materials for lithium-ion batteries.

BACKGROUND

A commonly used type of rechargeable battery is a lithium battery, suchas a lithium-ion or lithium-polymer battery. As battery-powered devicesbecome increasingly small and more powerful, batteries powering thesedevices need to store more energy in a smaller volume. Consequently, useof battery-powered devices may be facilitated by mechanisms forimproving the volumetric energy densities of batteries in the devices.

Lithium cobalt metal oxides or lithium transition metal oxides can beused in cathode active materials for lithium-ion batteries. The lithiumtransition metal oxides are derivations of lithium cobalt oxide. Thelithium cobalt metal oxides or transition metal oxides can be in theform of powder.

In Li-ion batteries, the cathode materials of different compositionstend to react chemically or electrochemically with the liquidelectrolyte that consists of a lithium salt (LiPF₆) in organic solvents(such as ethylene carbonate, ethyl-methylene carbonate), especially whenLi is extracted from the cathodes during charging. This is one of themajor reasons for causing short cycle life of the batteries. A coating,such as aluminum oxide (Al₂O₃), is normally applied to the cathodeparticles in order to mitigate the reaction between the cathode andelectrolyte and to prevent dissolution of the transition metals from thecathode into the electrolyte. Although the aluminum oxide coatingrenders necessary pretention, the coating often causes energy densityloss for the battery. There remains a need to develop coatings forimproved battery performance.

SUMMARY

In one aspect, the disclosure is directed to a cathode active materialincluding a plurality of cathode active compound particles. A coating isdisposed over each of the cathode active compound particles. The coatingcan include ZrO₂, La₂O₃, a mixture of Al₂O₃ and ZrO₂ or a mixture ofAl₂O₃ and La₂O₃.

In another aspect, the coating is a mixture of Al₂O₃ and ZrO₂. In somevariations, the cathode active material can have less than or equal to5000 ppm Zr. The cathode active material can have less than or equal to5000 ppm Al.

In another aspect, the coating can include a mixture of La₂O₃ and Al₂O₃.In some variations, the molar ratio of La to Al is from 0.01 to 5.0. Insome variations, aluminum is an amount from 20 ppm to 5000 ppm andlanthanum is in an amount from 20 ppm to 5000 ppm.

In further aspects, the disclosure is directed to a battery cell. Thebattery cell can include an anode comprising an anode current collectorand a cathode including the cathode active material described herein. Aseparator disposed between the anode and the cathode.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will be readily understood by the following detaileddescription in conjunction with the accompanying drawings, wherein likereference numerals designate like structural elements, and in which:

FIG. 1 is a top-down view of a battery cell in accordance with anillustrative embodiment;

FIG. 2A is a side view of a set of layers for a battery cell inaccordance with an illustrative embodiment;

FIG. 2B is a sectional view of a coated particle including a cathodeactive compound particle and a coating in accordance with anillustrative embodiment;

FIG. 3 is a plot of discharge capacity versus cycle count for cathodeactive materials including a mixture of Al₂O₃ and ZrO₂ coating onLi(Co_(0.97)Mn_(0.03))O₂ compared with Al₂O₃ coating or ZrO₂ coating onLi(CO_(0.97)Mn_(0.03))O₂, according to an illustrative embodiment;

FIG. 4 is a plot of average voltage versus cycle count for cathodeactive materials including a mixture of Al₂O₃ and ZrO₂ coating onLi(Co_(0.97)Mn_(0.03))O₂ compared with Al₂O₃ coating or ZrO₂ coating onLi(Co_(0.97)Mn_(0.03))O₂, according to an illustrative embodiment;

FIG. 5 is a plot of discharge energy versus cycle count for cathodeactive materials including a mixture of Al₂O₃ and ZrO₂ coating onLi(Co_(0.97)Mn_(0.03))O₂ compared with Al₂O₃ coating or ZrO₂ coating onLi(Co_(0.97)Mn_(0.03))O₂, according to an illustrative embodiment;

FIG. 6 is a plot of energy retention versus cycle count for cathodeactive materials including a mixture of Al₂O₃ and ZrO₂ coating onLi(Co_(0.97)Mn_(0.03))O₂ compared with Al₂O₃ coating or ZrO₂ coating onLi(Co_(0.97)Mn_(0.03))O₂, according to an illustrative embodiment;

FIG. 7 is a phase diagram of Al₂O₃ and ZrO₂ from Powder Metall. Met.Ceram., Vol. 33, 1994, p 486-490;

FIG. 8 is a plot of discharge capacity versus cycle count for cathodeactive materials including a mixture of Al₂O₃ and ZrO₂ coating onLi(Co_(0.97)Mn_(0.03))O₂ with different loadings at 1:1 molar ratio ofLa₂O₃ to Al₂O₃ compared with uncoated Li(Co_(0.97)Mn_(0.03))O₂ and Al₂O₃coating on Li(Co_(0.97)Mn_(0.03))O₂, according to an illustrativeembodiment;

FIG. 9 is a plot of average discharge voltage versus cycle count forcathode active materials including a mixture of Al₂O₃ and ZrO₂ coatingon Li(Co_(0.97)Mn_(0.03))O₂ with different loadings at 1:1 molar ratioof La₂O₃ to Al₂O₃ compared with uncoated Li(Co_(0.97)Mn_(0.03))O₂ andAl₂O₃ coating on Li(Co_(0.97)Mn_(0.03))O₂, according to an illustrativeembodiment;

FIG. 10 is a plot of discharge energy versus cycle count for cathodeactive materials including a mixture of Al₂O₃ and La₂O₃ coating onLi(Co_(0.97)Mn_(0.03))O₂ with different loadings at 1:1 molar ratio ofLa₂O₃ to Al₂O₃ compared with uncoated Li(Co_(0.97)Mn_(0.03))O₂ and Al₂O₃coating on Li(Co_(0.97)Mn_(0.03))O₂, according to an illustrativeembodiment;

FIG. 11 is a plot of energy retention versus cycle count for cathodeactive materials including a mixture of Al₂O₃ and La₂O₃ coating onLi(Co_(0.97)Mn_(0.03))O₂ with different loadings at 1:1 molar ratio ofLa₂O₃ to Al₂O₃ compared with uncoated Li(Co_(0.97)Mn_(0.03))O₂ and Al₂O₃coating on Li(Co_(0.97)Mn_(0.03))O₂, according to an illustrativeembodiment;

FIG. 12 is a phase diagram of Al₂O₃ and La₂O₃ (J. Alloys Compd., Vol.179, 1992, p 259-28);

FIG. 13 is a plot of discharge capacity versus cycle count for cathodeactive materials including the complex oxide ZnAl₂O₄ coating onLi(Co_(0.97)Mn_(0.03))O₂ compared with uncoated Li(Co_(0.97)Mn_(0.03))O₂and Al₂O₃ coating on Li(Co_(0.97)Mn_(0.03))O₂, according to anillustrative embodiment;

FIG. 14 is a plot of average discharge voltage versus cycle count forcathode active materials including the complex oxide ZnAl₂O₄ coating onLi(Co_(0.97)Mn_(0.03))O₂ compared with uncoated Li(Co_(0.97)Mn_(0.03))O₂and Al₂O₃ coating on Li(Co_(0.97)Mn_(0.03))O₂, according to anillustrative embodiment;

FIG. 15 is a plot of discharge energy versus cycle count for cathodeactive materials including the complex oxide ZnAl₂O₄ coating onLi(Co_(0.97)Mn_(0.03))O₂ compared with uncoated Li(Co_(0.97)Mn_(0.03))O₂and Al₂O₃ coating on Li(Co_(0.97)Mn_(0.03))O₂, according to anillustrative embodiment;

FIG. 16 is a plot of energy retention versus cycle count for cathodeactive materials including the complex oxide ZnAl₂O₄ coating onLi(Co_(0.97)Mn_(0.03))O₂ compared with uncoated Li(Co_(0.97)Mn_(0.03))O₂and Al₂O₃ coating on Li(Co_(0.97)Mn_(0.03))O₂, according to anillustrative embodiment;

FIG. 17 is a phase diagram of Al₂O₃ and ZnO. (Bur. Standards J.Research, 8(2) 280 1932; R.P.413).

DETAILED DESCRIPTION

The following description is presented to allow any person skilled inthe art to make and use the embodiments, and is provided in the contextof a particular application and its requirements. Various modificationsto the disclosed embodiments will be readily apparent to those skilledin the art, and the general principles defined herein may be applied toother embodiments and applications without departing from the spirit andscope of the present disclosure. It should be understood that thefollowing descriptions are not intended to limit the embodiments to onepreferred embodiment. To the contrary, it is intended to coveralternatives, modifications, and equivalents as can be included withinthe spirit and scope of the described embodiments as defined by theappended claims. Thus, the disclosure is not limited to the embodimentsshown, but is to be accorded the widest scope consistent with theprinciples and features disclosed herein.

As used herein, all compositions referenced for cathode active materialsrepresent those of as-prepared materials (i.e., “virgin” materials)unless otherwise indicated. Materials of these compositions have not yetbeen exposed to additional processes, such as de-lithiation andlithiation during, respectively, charging and discharging of alithium-ion battery.

Overview

The disclosure provides the use of various oxides mixture or complexoxides as coatings for the cathode active compound particles oflithium-ion (Li-ion) batteries or other types of Li batteries. Thecoated cathode active materials have improved properties over analuminum oxide coating and an uncoated cathode active material. Lithiumcobalt oxides or lithium transition-metal oxides can be used in cathodeactive materials for commercial lithium-ion batteries. The lithiumtransition-metal oxides are variations or derivatives of lithium cobaltoxides. The performance of such cathode active materials can beincreased by improving its discharge capacity, average voltage,discharge energy, and energy retention.

The disclosure provides surface coatings for cathode materials of Li-ionbatteries and other Li batteries that demonstrate improved energy and/orenergy retention. The surface coatings may include mixed oxides, such asa mixture of Al₂O₃ and ZrO₂. The surface coatings may also includecomplex oxides, such as ZnAl₂O₄. Without limitation, these coatingcompositions are applied to the cathodes of Li-ion batteries or othertypes of Li batteries (e.g., substituted lithium cobalt oxides orlithium manganese cobalt nickel oxides), the batteries can demonstrateeither improved discharge capacity, increased average discharge voltage,increased energy, and/or energy retention over the uncoated cathodeactive compound particles, and the conventional alumina coating on thecathode active compound particles.

The performance of batteries can be improved using coatings on cathodeactive materials that provide increased discharge capacity, averagevoltage, discharge energy, and energy retention. These and other needsare addressed by the disclosure herein.

FIG. 1 presents a top-down view of a battery cell 100 in accordance withan embodiment. The battery cell 100 may correspond to a lithium-ion orlithium-polymer battery cell that is used to power a device used in aconsumer, medical, aerospace, defense, and/or transportationapplication. The battery cell 100 includes a stack 102 containing anumber of layers that include a cathode with a cathode active material,a separator, and an anode with an anode active material. Morespecifically, the stack 102 may include one strip of cathode activematerial (e.g., aluminum foil coated with a lithium compound) and onestrip of anode active material (e.g., copper foil coated with carbon).The stack 102 also includes one strip of separator material (e.g.,conducting polymer electrolyte) disposed between the one strip ofcathode active material and the one strip of anode active material. Thecathode, anode, and separator layers may be left flat in a planarconfiguration or may be wrapped into a wound configuration (e.g., a“jelly roll”).

Enclosures can include, without limitations, pouches, such as flexiblepouches, rigid containers, and the like. Returning to FIG. 1 , duringassembly of the battery cell 100, the stack 102 is enclosed in anenclosure. The stack 102 may be in a planar or wound configuration,although other configurations are possible. Flexible pouch can be formedby folding a flexible sheet along a fold line 112. For example, theflexible sheet may be made of aluminum with a polymer film, such aspolypropylene. After the flexible sheet is folded, the flexible sheetcan be sealed, for example, by applying heat along a side seal 110 andalong a terrace seal 108. The flexible pouch may be less than 120microns thick to improve the packaging efficiency of the battery cell100, the density of battery cell 100, or both.

The stack 102 can also include a set of conductive tabs 106 coupled tothe cathode and the anode. The conductive tabs 106 may extend throughseals in the enclosure (for example, formed using sealing tape 104) toprovide terminals for the battery cell 100. The conductive tabs 106 maythen be used to electrically couple the battery cell 100 with one ormore other battery cells to form a battery pack.

Batteries can be combined in a battery pack in any configuration. Forexample, the battery pack may be formed by coupling the battery cells ina series, parallel, or a series-and-parallel configuration. Such coupledcells may be enclosed in a hard case to complete the battery pack, ormay be embedded within an enclosure of a portable electronic device,such as a laptop computer, tablet computer, mobile phone, personaldigital assistant (PDA), digital camera, and/or portable media player.

FIG. 2A presents a side view of a set of layers for a battery cell(e.g., the battery cell 100 of FIG. 1 ) in accordance with the disclosedembodiments. The set of layers may include a cathode current collector202, a cathode active material 204, a separator 206, an anode activematerial 208, and an anode current collector 210. The cathode currentcollector 202 and the cathode active material 204 may form a cathode forthe battery cell, and the anode current collector 210 and the anodeactive material 208 may form an anode for the battery cell. To createthe battery cell, the set of layers may be stacked in a planarconfiguration, or stacked and then wrapped into a wound configuration.

As mentioned above, the cathode current collector 202 may be aluminumfoil, the cathode active material 204 may be a lithium compound, theanode current collector 210 may be copper foil, the anode activematerial 208 may be carbon, and the separator 206 may include aconducting polymer electrolyte.

It will be understood that the cathode active materials described hereincan be used in conjunction with any battery cells or components thereofknown in the art. For example, in addition to wound battery cells, thelayers may be stacked and/or used to form other types of battery cellstructures, such as bi-cell structures. All such battery cell structuresare known in the art.

In further variations, a cathode active material comprises a cathodeactive compound particle and a coating. FIG. 2B is a sectional view of acoated particle including a cathode active particle and a coating inaccordance with an illustrative embodiment. As shown, a coated cathodeactive compound particle 212 can include a cathode active compoundparticle or a cathode active compound particle 216 and a coating 214.

The coating can be an oxide material. In some variations, the coatingmay be a layer of material in contact with a surface of the cathodeactive compound particle or a reaction layer formed along the surface ofthe cathode active compound particle. In some variations, the coatingcan include an oxide mixture (e.g. a mixture of Al₂O₃ and ZrO₂, or amixture of Al₂O₃ and La₂O₃). In some variations, the coating can includea complex oxide, such as ZnAl₂O₄.

In various embodiments, the performance of batteries including thecathode active material can increase battery capacity and/or reduce theloss of available power in a fully charged battery over time.

The coating can be in any amount known in the art. In some variations,amount of coating may be less than or equal to 7 wt. % of the totalparticle. In some variations, amount of coating may be less than orequal to 5 wt. % of the total particle. In some variations, amount ofcoating may be less than or equal to 0.8 wt. % of the total particle. Insome variations, amount of coating may be less than or equal to 0.6 wt.% of the total particle. In some variations, amount of coating may beless than or equal to 0.4 wt. % of the total particle. In somevariations, amount of coating may be less than or equal to 0.3 wt. % ofthe total particle. In some variations, amount of coating may be lessthan or equal to 0.2 wt. % of the total particle. In some variations,amount of coating may be less than or equal to 0.1 wt. % of the totalparticle. In various aspects, the amount can be chosen such that acapacity of the cathode active material is not negatively impacted.

The coating may include multiple layers of coating material. The coatingmay also be a continuous coating or a discontinuous coating.Non-limiting examples of discontinuous coatings include coatings withvoids or cracks and coatings formed of particles with gaps therebetween. Other types of discontinuous coatings are possible.

A powder comprising the particles described herein can be used as acathode active material in a lithium ion battery. Such cathode activematerials can tolerate voltages equal to or higher than conventionalmaterials (i.e., relative to a Li/Li⁺ redox couple) without capacityfade. Capacity fade degrades battery performance and may result from astructural instability of the cathode active material, a side reactionwith electrolyte at high voltage, surface instability, dissolution ofcathode active material into the electrolyte, or some combinationthereof.

In various aspects, the cathode active materials described herein canresult in lithium ion batteries that can be charged at high voltageswithout capacity fade. Without wishing to be held to a specificmechanisms or mode of action, the compounds may impede or retardstructural deviations from an α-NaFeO₂ crystal structure during chargingto/at higher voltages.

Batteries having cathode active materials that include the disclosedcoatings can show improved battery performance. For example, the mixtureoxide coatings particles provide for an increased battery capacity andan increase average voltage and also an increased discharge energy overcycles.

Mixture of Al₂O₃ and ZrO₂

In some variations, the molar ratio of Al to Zr for the mixture of Al₂O₃and ZrO₂ is equal to or less than 5.0. In some variations, the molarratio of Al to Zr for the mixture of Al₂O₃ and ZrO₂ is equal to or lessthan 4. In some variations, the molar ratio of Al to Zr for the mixtureof Al₂O₃ and ZrO₂ is equal to or less than 2. In some variations, themolar ratio of Al to Zr for the mixture of Al₂O₃ and ZrO₂ is equal to orless than 1. In some variations, the molar ratio of Al to Zr for themixture of Al₂O₃ and ZrO₂ is equal to or less than 0.5. In somevariations, the molar ratio of Al to Zr for the mixture of Al₂O₃ andZrO₂ is equal to or less than 0.28. In some variations, the molar ratioof Al to Zr for the mixture of Al₂O₃ and ZrO₂ is equal to or less than0.26. In some variations, the molar ratio of Al to Zr for the mixture ofAl₂O₃ and ZrO₂ is equal to or less than 0.23. In some variations, themolar ratio of Al to Zr for the mixture of Al₂O₃ and ZrO₂ is equal to orless than 0.20. In some variations, the molar ratio of Al to Zr for themixture of Al₂O₃ and ZrO₂ is equal to or less than 0.17. In somevariations, the molar ratio of Al to Zr for the mixture of Al₂O₃ andZrO₂ is equal to or less than 0.13. In some variations, the molar ratioof Al to Zr for the mixture of Al₂O₃ and ZrO₂ is equal to or less than0.11. In some variations, the molar ratio of Al to Zr for the mixture ofAl₂O₃ and ZrO₂ is equal to or less than 0.09. In some variations, themolar ratio of Al to Zr for the mixture of Al₂O₃ and ZrO₂ is equal to orless than 0.07. In some variations, the molar ratio of Al to Zr for themixture of Al₂O₃ and ZrO₂ is equal to or less than 0.06. In somevariations, the molar ratio of Al to Zr for the mixture of Al₂O₃ andZrO₂ is equal to or less than 0.05. In some variations, the molar ratioof Al to Zr for the mixture of Al₂O₃ and ZrO₂ is equal to or less than0.04. In some variations, the molar ratio of Al to Zr for the mixture ofAl₂O₃ and ZrO₂ is equal to or less than 0.03. In some variations, themolar ratio of Al to Zr for the mixture of Al₂O₃ and ZrO₂ is equal to orless than 0.02.

In certain variations, the mixture of Al₂O₃ and ZrO₂ has equal to orless than 3000 ppm aluminum. In certain variations, the mixture of Al₂O₃and ZrO₂ has equal to or less than 2000 ppm aluminum. In certainvariations, the mixture of Al₂O₃ and ZrO₂ has equal to or less than 1000ppm aluminum. In certain variations, the mixture of Al₂O₃ and ZrO₂ hasequal to or less than 500 ppm aluminum. In certain variations, themixture of Al₂O₃ and ZrO₂ has equal to or less than 300 ppm aluminum. Incertain variations, the mixture of Al₂O₃ and ZrO₂ has equal to or lessthan 230 ppm aluminum. In certain variations, the mixture of Al₂O₃ andZrO₂ has equal to or less than 200 ppm aluminum. In certain variations,the mixture of Al₂O₃ and ZrO₂ has equal to or less than 170 ppmaluminum. In certain variations, the mixture of Al₂O₃ and ZrO₂ has equalto or less than 135 ppm aluminum. In certain variations, the mixture ofAl₂O₃ and ZrO₂ has equal to or less than 120 ppm aluminum. In certainvariations, the mixture of Al₂O₃ and ZrO₂ has equal to or less than 100ppm aluminum. In certain variations, the mixture of Al₂O₃ and ZrO₂ hasequal to or less than 90 ppm aluminum. In certain variations, themixture of Al₂O₃ and ZrO₂ has equal to or less than 80 ppm aluminum. Incertain variations, the mixture of Al₂O₃ and ZrO₂ has equal to or lessthan 65 ppm aluminum. In certain variations, the mixture of Al₂O₃ andZrO₂ has equal to or less than 50 ppm aluminum. In certain variations,the mixture of Al₂O₃ and ZrO₂ has equal to or less than 45 ppm aluminum.In certain variations, the mixture of Al₂O₃ and ZrO₂ has equal to orless than 35 ppm aluminum. In certain variations, the mixture of Al₂O₃and ZrO₂ has equal to or less than 15 ppm aluminum.

In certain variations, the mixture of Al₂O₃ and ZrO₂ has equal to orgreater than 10 ppm aluminum. In certain variations, the mixture ofAl₂O₃ and ZrO₂ has equal to or greater than 20 ppm aluminum. In certainvariations, the mixture of Al₂O₃ and ZrO₂ has equal to or greater than30 ppm aluminum. In certain variations, the mixture of Al₂O₃ and ZrO₂has equal to or greater than 40 ppm aluminum. In certain variations, themixture of Al₂O₃ and ZrO₂ has equal to or greater than 55 ppm aluminum.In certain variations, the mixture of Al₂O₃ and ZrO₂ has equal to orgreater than 60 ppm aluminum. In certain variations, the mixture ofAl₂O₃ and ZrO₂ has equal to or greater than 70 ppm aluminum. In certainvariations, the mixture of Al₂O₃ and ZrO₂ has equal to or greater than85 ppm aluminum. In certain variations, the mixture of Al₂O₃ and ZrO₂has equal to or greater than 95 ppm aluminum.

In certain variations, the mixture of Al₂O₃ and ZrO₂ has equal to orgreater than 100 ppm zirconium. In certain variations, the mixture ofAl₂O₃ and ZrO₂ has equal to or greater than 200 ppm zirconium. Incertain variations, the mixture of Al₂O₃ and ZrO₂ has equal to orgreater than 500 ppm zirconium. In certain variations, the mixture ofAl₂O₃ and ZrO₂ has equal to or greater than 600 ppm zirconium. Incertain variations, the mixture of Al₂O₃ and ZrO₂ has equal to orgreater than 700 ppm zirconium. In certain variations, the mixture Al₂O₃and ZrO₂ has equal to or greater than 800 ppm zirconium. In certainvariations, the mixture of Al₂O₃ and ZrO₂ has equal to or greater than900 ppm zirconium. In certain variations, the mixture of Al₂O₃ and ZrO₂has equal to or greater than 1000 ppm zirconium. In certain variations,the mixture of Al₂O₃ and ZrO₂ has equal to or greater than 1100 ppmzirconium. In certain variations, the mixture of Al₂O₃ and ZrO₂ hasequal to or greater than 1200 ppm zirconium. In certain variations, themixture of Al₂O₃ and ZrO₂ has equal to or greater than 1300 ppmzirconium. In certain variations, the mixture of Al₂O₃ and ZrO₂ hasequal to or greater than 1400 ppm zirconium.

In certain variations, the mixture of Al₂O₃ and ZrO₂ has equal to orless than 2000 ppm zirconium. In certain variations, the mixture ofAl₂O₃ and ZrO₂ has equal to or less than 1500 ppm zirconium. In certainvariations, the mixture of Al₂O₃ and ZrO₂ has equal to or less than 1400ppm zirconium. In certain variations, the mixture of Al₂O₃ and ZrO₂ hasequal to or less than 1300 ppm zirconium. In certain variations, themixture of Al₂O₃ and ZrO₂ has equal to or less than 1200 ppm zirconium.In certain variations, the mixture of Al₂O₃ and ZrO₂ has equal to orless than 1100 ppm zirconium. In certain variations, the mixture ofAl₂O₃ and ZrO₂ has equal to or less than 1000 ppm zirconium. In certainvariations, the mixture of Al₂O₃ and ZrO₂ has equal to or less than 900ppm zirconium. In certain variations, the mixture of Al₂O₃ and ZrO₂ hasequal to or less than 800 ppm zirconium.

In certain variations, a battery including a mixture of Al₂O₃ and ZrO₂coated cathode active materials has a discharge energy of at least 710Wh/kg after 25 cycles. In certain variations, a battery including amixture of Al₂O₃ and ZrO₂ coated cathode active materials has adischarge energy of at least 712 Wh/kg after 25 cycles. In certainvariations, a battery including a mixture of Al₂O₃ and ZrO₂ coatedcathode active materials has a discharge energy of at least 714 Wh/kgafter 25 cycles. In certain variations, a battery including a mixture ofAl₂O₃ and ZrO₂ coated cathode active materials has a discharge energy ofat least 716 Wh/kg after 25 cycles. In certain variations, a batteryincluding a mixture of Al₂O₃ and ZrO₂ coated cathode active materialshas a discharge energy of at least 718 Wh/kg after 25 cycles. In certainvariations, a battery including a mixture of Al₂O₃ and ZrO₂ coatedcathode active materials has a discharge energy of at least 720 Wh/kgafter 25 cycles.

In some variations, the battery including a mixture of Al₂O₃ and ZrO₂coated cathode active materials has an energy retention of at least 85%after 30 charge-discharge cycles. In some variations, the batteryincluding a mixture of Al₂O₃ and ZrO₂ coated cathode active materialshas an energy retention of at least 90% after 30 charge-dischargecycles. In some variations, the battery including a mixture of Al₂O₃ andZrO₂ coated cathode active materials has an energy retention of at least91% after 30 charge-discharge cycles. In some variations, the batteryincluding a mixture of Al₂O₃ and ZrO₂ coated cathode active materialshas an energy retention of at least 92% after 30 charge-dischargecycles. In some variations, the battery including a mixture of Al₂O₃ andZrO₂ coated cathode active materials has an energy retention of at least93% after 30 charge-discharge cycles. In some variations, the batteryincluding a mixture of Al₂O₃ and ZrO₂ coated cathode active materialshas an energy retention of at least 94% after 30 charge-dischargecycles. In some variations, the battery including a mixture of Al₂O₃ andZrO₂ coated cathode active materials has an energy retention of at least95% after 30 charge-discharge cycles. In some variations, the batteryincluding a mixture of Al₂O₃ and ZrO₂ coated cathode active materialshas an energy retention of at least 96% after 30 charge-dischargecycles. In some variations, the battery including a mixture of Al₂O₃ andZrO₂ coated cathode active materials has an energy retention of at least97% after 30 charge-discharge cycles. In some variations, the batteryincluding a mixture of Al₂O₃ and ZrO₂ coated cathode active materialshas an energy retention of at least 98% after 30 charge-dischargecycles.

Mixture of Al₂O₃ and La₂O₃

In some variations, the mole ratio of La to Al for the mixture of Al₂O₃and La₂O₃ is equal to or less than 5. In some variations, the molarratio of La to Al for the mixture of Al₂O₃ and La₂O₃ is equal to or lessthan 4. In some variations, the molar ratio of La to Al for the mixtureof Al₂O₃ and La₂O₃ is equal to or less than 3. In some variations, themolar ratio of La to Al for the mixture of Al₂O₃ and La₂O₃ is equal toor less than 1.0. In some variations, the molar ratio of La to Al forthe mixture of Al₂O₃ and La₂O₃ is equal to or less than 0.9. In somevariations, the molar ratio of La to Al for the mixture of Al₂O₃ andLa₂O₃ is equal to or less than 0.8. In some variations, the molar ratioof La to Al for the mixture of Al₂O₃ and La₂O₃ is equal to or less than1.2. In some variations, the molar ratio of La to Al for the mixture ofAl₂O₃ and La₂O₃ is equal to or less than 1.1. In some variations, themolar ratio of La to Al for the mixture of Al₂O₃ and La₂O₃ is equal toor less than 1.0. In some variations, the molar ratio of La to Al forthe mixture of A Al₂O₃ and La₂O₃ is equal to or less than 0.9. In somevariations, the molar ratio of La to Al for the mixture of Al₂O₃ andLa₂O₃ is equal to or less than 0.8.

In some variations, the molar ratio of La to Al for the mixture of Al₂O₃and La₂O₃ is equal to or greater than 0.1. In some variations, the molarratio of La to Al for the mixture of Al₂O₃ and La₂O₃ is equal to orgreater than 0.2. In some variations, the molar ratio of La to Al forthe mixture of Al₂O₃ and La₂O₃ is equal to or greater than 0.3. In somevariations, the molar ratio of La to Al for the mixture of Al₂O₃ andLa₂O₃ is equal to or greater than 0.4. In some variations, the molarratio of La to Al for the mixture of Al₂O₃ and La₂O₃ is equal to orgreater than 0.5. In some variations, the molar ratio of La to Al forthe mixture of Al₂O₃ and La₂O₃ is equal to or greater than 0.6. In somevariations, the molar ratio of La to Al for the mixture of Al₂O₃ andLa₂O₃ is equal to or greater than 0.7. In some variations, the molarratio of La to Al for the mixture of Al₂O₃ and La₂O₃ is equal to orgreater than 0.8. In some variations, the molar ratio of La to Al forthe mixture of Al₂O₃ and La₂O₃ is equal to or greater than 0.9. In somevariations, the molar ratio of La to Al for the mixture of Al₂O₃ andLa₂O₃ is equal to or greater than 1.0. In some variations, the molarratio of La to Al for the mixture of Al₂O₃ and La₂O₃ is equal to orgreater than 1.1. In some variations, the molar ratio of La to Al forthe mixture of Al₂O₃ and La₂O₃ is equal to or greater than 1.2.

In certain variations, the mixture of Al₂O₃ and La₂O₃ has aluminum from20 ppm to 5000 ppm.

In certain variations, the mixture of Al₂O₃ and La₂O₃ has equal to orgreater than 20 ppm aluminum. In certain variations, the mixture ofAl₂O₃ and La₂O₃ has equal to or greater than 40 ppm aluminum. In certainvariations, the mixture of Al₂O₃ and La₂O₃ has equal to or greater than60 ppm aluminum. In certain variations, the mixture of Al₂O₃ and La₂O₃has equal to or greater than 80 ppm aluminum. In certain variations, themixture of Al₂O₃ and La₂O₃ has equal to or greater than 100 ppmaluminum. In certain variations, the mixture of Al₂O₃ and La₂O₃ hasequal to or greater than 120 ppm aluminum. In certain variations, themixture of Al₂O₃ and La₂O₃ has equal to or greater than 150 ppmaluminum. In certain variations, the mixture of Al₂O₃ and La₂O₃ hasequal to or greater than 200 ppm aluminum. In certain variations, themixture of Al₂O₃ and La₂O₃ has equal to or greater than 250 ppmaluminum. In certain variations, the mixture of Al₂O₃ and La₂O₃ hasequal to or greater than 300 ppm aluminum. In certain variations, themixture of Al₂O₃ and La₂O₃ has equal to or greater than 500 ppmaluminum. In certain variations, the mixture of Al₂O₃ and La₂O₃ hasequal to or greater than 1000 ppm aluminum. In certain variations, themixture of Al₂O₃ and La₂O₃ has equal to or greater than 2000 ppmaluminum. In certain variations, the mixture of Al₂O₃ and La₂O₃ hasequal to or greater than 3000 ppm aluminum. In certain variations, themixture of Al₂O₃ and La₂O₃ has equal to or greater than 4000 ppmaluminum.

In certain variations, the mixture of Al₂O₃ and La₂O₃ has equal to orless than 5000 ppm aluminum. In certain variations, the mixture of Al₂O₃and La₂O₃ has equal to or less than 4000 ppm aluminum. In certainvariations, the mixture of Al₂O₃ and La₂O₃ has equal to or less than3000 ppm aluminum. In certain variations, the mixture of Al₂O₃ and La₂O₃has equal to or less than 2500 ppm aluminum. In certain variations, themixture of Al₂O₃ and La₂O₃ has equal to or less than 2000 ppm aluminum.In certain variations, the mixture of Al₂O₃ and La₂O₃ has equal to orless than 1000 ppm aluminum. In certain variations, the mixture of Al₂O₃and La₂O₃ has equal to or less than 500 ppm aluminum. In certainvariations, the mixture of Al₂O₃ and La₂O₃ has equal to or less than 340ppm aluminum. In certain variations, the mixture of Al₂O₃ and La₂O₃ hasequal to or less than 300 ppm aluminum. In certain variations, themixture of Al₂O₃ and La₂O₃ has equal to or less than 250 ppm aluminum.In certain variations, the mixture of Al₂O₃ and La₂O₃ has equal to orless than 200 ppm aluminum. In certain variations, the mixture of Al₂O₃and La₂O₃ has equal to or less than 150 ppm aluminum. In certainvariations, the mixture of Al₂O₃ and La₂O₃ has equal to or less than 100ppm aluminum. In certain variations, the mixture of Al₂O₃ and La₂O₃ hasequal to or less than 80 ppm aluminum. In certain variations, themixture of Al₂O₃ and La₂O₃ has equal to or less than 60 ppm aluminum. Incertain variations, the mixture of Al₂O₃ and La₂O₃ has equal to or lessthan 40 ppm aluminum. In certain variations, the mixture of Al₂O₃ andLa₂O₃ has lanthanum from 20 ppm to 5000 ppm.

In certain variations, the mixture of Al₂O₃ and La₂O₃ has equal to orgreater than 20 ppm lanthanum. In certain variations, the mixture ofAl₂O₃ and La₂O₃ has equal to or greater than 50 ppm lanthanum. Incertain variations, the mixture of Al₂O₃ and La₂O₃ has equal to orgreater than 100 ppm lanthanum. In certain variations, the mixture ofAl₂O₃ and La₂O₃ has equal to or greater than 200 ppm lanthanum. Incertain variations, the mixture of Al₂O₃ and La₂O₃ has equal to orgreater than 300 ppm lanthanum. In certain variations, the mixture ofAl₂O₃ and La₂O₃ has equal to or greater than 400 ppm lanthanum. Incertain variations, the mixture of Al₂O₃ and La₂O₃ has equal to orgreater than 500 ppm lanthanum. In certain variations, the mixture ofAl₂O₃ and La₂O₃ has equal to or greater than 600 ppm lanthanum. Incertain variations, the mixture of Al₂O₃ and La₂O₃ has equal to orgreater than 700 ppm lanthanum. In certain variations, the mixture ofAl₂O₃ and La₂O₃ has equal to or greater than 800 ppm lanthanum. Incertain variations, the mixture of Al₂O₃ and La₂O₃ has equal to orgreater than 900 ppm lanthanum. In certain variations, the mixture ofAl₂O₃ and La₂O₃ has equal to or greater than 1000 ppm lanthanum. Incertain variations, the mixture of Al₂O₃ and La₂O₃ has equal to orgreater than 1100 ppm lanthanum. In certain variations, the mixture ofAl₂O₃ and La₂O₃ has equal to or greater than 1200 ppm lanthanum. Incertain variations, the mixture of Al₂O₃ and La₂O₃ has equal to orgreater than 1300 ppm lanthanum. In certain variations, the mixture ofAl₂O₃ and La₂O₃ has equal to or greater than 1400 ppm lanthanum. Incertain variations, the mixture of Al₂O₃ and La₂O₃ has equal to orgreater than 1500 ppm lanthanum. In certain variations, the mixture ofAl₂O₃ and La₂O₃ has equal to or greater than 2000 ppm lanthanum. Incertain variations, the mixture of Al₂O₃ and La₂O₃ has equal to orgreater than 2500 ppm lanthanum. In certain variations, the mixture ofAl₂O₃ and La₂O₃ has equal to or greater than 3000 ppm lanthanum. Incertain variations, the mixture of Al₂O₃ and La₂O₃ has equal to orgreater than 4000 ppm lanthanum.

In certain variations, the mixture of Al₂O₃ and La₂O₃ has equal to orless than 5000 ppm lanthanum. In certain variations, the mixture ofAl₂O₃ and La₂O₃ has equal to or less than 4000 ppm lanthanum. In certainvariations, the mixture of Al₂O₃ and La₂O₃ has equal to or less than3000 ppm lanthanum. In certain variations, the mixture of Al₂O₃ andLa₂O₃ has equal to or less than 2500 ppm lanthanum. In certainvariations, the mixture of Al₂O₃ and La₂O₃ has equal to or less than2000 ppm lanthanum. In certain variations, the mixture of Al₂O₃ andLa₂O₃ has equal to or less than 1500 ppm lanthanum. In certainvariations, the mixture of Al₂O₃ and La₂O₃ has equal to or less than1300 ppm lanthanum. In certain variations, the mixture of Al₂O₃ andLa₂O₃ has equal to or less than 1100 ppm lanthanum. In certainvariations, the mixture of Al₂O₃ and La₂O₃ has equal to or less than 900ppm lanthanum. In certain variations, the mixture of Al₂O₃ and La₂O₃ hasequal to or less than 700 ppm lanthanum. In certain variations, themixture of Al₂O₃ and La₂O₃ has equal to or less than 500 ppm lanthanum.In certain variations, the mixture of Al₂O₃ and La₂O₃ has equal to orless than 300 ppm lanthanum. In certain variations, the mixture of Al₂O₃and La₂O₃ has equal to or less than 200 ppm lanthanum. In certainvariations, the mixture of Al₂O₃ and La₂O₃ has equal to or less than 100ppm lanthanum. In certain variations, the mixture of Al₂O₃ and La₂O₃ hasequal to or less than 50 ppm lanthanum.

In certain variations, a battery including a mixture of Al₂O₃ and La₂O₃coated cathode active materials has a discharge energy of at least 710Wh/kg after 25 cycles. In certain variations, a battery including amixture of Al₂O₃ and La₂O₃ coated cathode active materials has adischarge energy of at least 715 Wh/kg after 25 cycles. In certainvariations, a battery including a mixture of Al₂O₃ and La₂O₃ coatedcathode active materials has a discharge energy of at least 720 Wh/kgafter 25 cycles. In certain variations, a battery including a mixture ofAl₂O₃ and La₂O₃ coated cathode active materials has a discharge energyof at least 725 Wh/kg after 25 cycles. In certain variations, a batteryincluding a mixture of Al₂O₃ and La₂O₃ coated cathode active materialshas a discharge energy of at least 730 Wh/kg after 25 cycles. In certainvariations, a battery including a mixture of Al₂O₃ and La₂O₃ coatedcathode active materials has a discharge energy of at least 735 Wh/kgafter 25 cycles.

In some variations, the battery including a mixture of Al₂O₃ and La₂O₃coated cathode active materials has an energy retention of at least 85%after 30 charge-discharge cycles. In some variations, the batteryincluding a mixture of Al₂O₃ and La₂O₃ coated cathode active materialshas an energy retention of at least 90% after 30 charge-dischargecycles. In some variations, the battery including a mixture of Al₂O₃ andLa₂O₃ coated cathode active materials has an energy retention of atleast 91% after 30 charge-discharge cycles. In some variations, thebattery including a mixture of Al₂O₃ and La₂O₃ coated cathode activematerials has an energy retention of at least 92% after 30charge-discharge cycles. In some variations, the battery including amixture of Al₂O₃ and La₂O₃ coated cathode active materials has an energyretention of at least 93% after 30 charge-discharge cycles. In somevariations, the battery including a mixture of Al₂O₃ and La₂O₃ coatedcathode active materials has an energy retention of at least 94% after30 charge-discharge cycles. In some variations, the battery including amixture of Al₂O₃ and La₂O₃ coated cathode active materials has an energyretention of at least 95% after 30 charge-discharge cycles. In somevariations, the battery including a mixture of Al₂O₃ and La₂O₃ coatedcathode active materials has an energy retention of at least 96% after30 charge-discharge cycles. In some variations, the battery including amixture of Al₂O₃ and La₂O₃ coated cathode active materials has an energyretention of at least 97% after 30 charge-discharge cycles. In somevariations, the battery including a mixture of Al₂O₃ and La₂O₃ coatedcathode active materials has an energy retention of at least 98% after30 charge-discharge cycles.

In certain variations, a battery including a complex oxide ZnAl₂O₄coated cathode active materials has a discharge energy of at least 715Wh/kg after 25 cycles. In certain variations, a battery including acomplex oxide ZnAl₂O₄ coated cathode active materials has a dischargeenergy of at least 720 Wh/kg after 25 cycles. In certain variations, abattery including a complex oxide ZnAl₂O₄ coated cathode activematerials has a discharge energy of at least 725 Wh/kg after 25 cycles.In certain variations, a battery including a complex oxide ZnAl₂O₄coated cathode active materials has a discharge energy of at least 730Wh/kg after 25 cycles. In certain variations, a battery including acomplex oxide ZnAl₂O₄ coated cathode active materials has a dischargeenergy of at least 735 Wh/kg after 25 cycles. In certain variations, abattery including a complex oxide ZnAl₂O₄ coated cathode activematerials has a discharge energy of at least 740 Wh/kg after 25 cycles.

In some variations, the battery including a complex oxide ZnAl₂O₄ coatedcathode active materials has an energy retention of at least 85% after30 charge-discharge cycles. In some variations, the battery including acomplex oxide ZnAl₂O₄ coated cathode active materials has an energyretention of at least 90% after 30 charge-discharge cycles. In somevariations, the battery including a complex oxide ZnAl₂O₄ coated cathodeactive materials has an energy retention of at least 91% after 30charge-discharge cycles. In some variations, the battery including acomplex oxide ZnAl₂O₄ coated cathode active materials has an energyretention of at least 92% after 30 charge-discharge cycles. In somevariations, the battery including a complex oxide ZnAl₂O₄ coated cathodeactive materials has an energy retention of at least 93% after 30charge-discharge cycles. In some variations, the battery including acomplex oxide ZnAl₂O₄ coated cathode active materials has an energyretention of at least 94% after 30 charge-discharge cycles. In somevariations, the battery including a complex oxide ZnAl₂O₄ coated cathodeactive materials has an energy retention of at least 95% after 30charge-discharge cycles. In some variations, the battery including acomplex oxide ZnAl₂O₄ coated cathode active materials has an energyretention of at least 96% after 30 charge-discharge cycles. In somevariations, the battery including a complex oxide ZnAl₂O₄ coated cathodeactive materials has an energy retention of at least 97% after 30charge-discharge cycles. In some variations, the battery including acomplex oxide ZnAl₂O₄ coated cathode active materials has an energyretention of at least 98% after 30 charge-discharge cycles.

The coated powder can be used as a cathode active material for lithiumion batteries, as described herein. These cathode active materialsassist energy storage by releasing and storing lithium ions during,respectively, charging and discharging of a lithium-ion battery.

Without wishing to be limited to a specific mechanism or mode of action,the characteristics of the powder can provide improved batteryperformance when the powder is used as a cathode active material. Thepowder comprising the disclosed oxide mixture coatings or complex oxidecoating described herein have increased capacity and increased stabilityover an oxide coating, such as an Al₂O₃ coating or a ZrO₂ coating.Batteries comprising the powder as a cathode active material have anincreased discharge capacity, an increased average voltage, an increaseddischarge energy, and an increased energy retention.

Cathode Active Compounds

The coating is disposed over cathode active compounds. Specifically, invarious aspects, the coating is disposed over cathode active compoundparticles. The coated cathode active compounds can be used as cathodeactive materials in lithium-ion batteries.

In some variations, this disclosure is directed to a cathode activeprecursor compound, or particles (e.g., a powder) comprising the cathodeactive precursor compound, represented by Formula (Ia):Ni_(a)Mn_(b)Co_(c)M¹ _(d)O_(e)  (Ia)In Formula (Ia), M¹ is selected from B, Na, Mg, Al, Si, K, Ca, Sc, Ti,V, Cr, Fe, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ru, Ag, In, La and anycombination thereof; 0≤a≤1; 0≤b≤1; 0≤c≤1; a+b+c>0; 0≤d≤0.5; a+b+d>0; and1≤e≤5. Compounds of Formula (Ia) include at least one of Ni, Mn, or Co(i.e., a+b+c>0). Moreover, the compounds include at least one of Ni, Mn,or M¹ (i.e., a+b+d>0).

In some variations, this disclosure is directed to a cathode activecompound, or particles (e.g., a powder) comprising the cathode activecompound, represented by Formula (Ib):Li_(1+f)Ni_(a)Mn_(b)Co_(c)M¹ _(d)O_(e)  (Ib)It will be appreciated that the lithiated mixed-metal oxides may beprepared using the mixed-metal oxides associated with Formula (Ia), aswill be discussed below. In Formula (Ib), M¹ is selected from B, Na, Mg,Al, Si, K, Ca, Sc, Ti, V, Cr, Fe, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ru, Ag,In, La and combinations thereof; −0.1≤f≤1.0; 0≤a≤1; 0≤b≤1; 0≤c≤1;a+b+c>0; 0≤d≤0.5; a+b+d>0; and 1.9≤e≤3. Compounds of Formula (Ib)include at least one of Ni, Mn, or Co (i.e., a+b+c>0). Moreover, thecompounds include at least one of Ni, Mn, or M¹ (i.e., a+b+d>0). As usedherein, all compounds referenced for the lithiated mixed-metal oxidesrepresent those of as-prepared materials (i.e., “virgin” materials)unless otherwise indicated. Such compounds have not yet been exposed toadditional chemical processes, such as de-lithiation and lithiationduring, respectively, charging and discharging. In some instances,0≤f≤0.5. In some instances, 1.9≤e≤2.7. In further instances, 1.9≤e≤2.1.

In some instances, 0≤f≤1.0 and d=0. In these instances, no contentassociated with M¹ is present in the particles. Further, in someinstances, d=0 and f≥0.20. In some instances, d=0 and f≥0.40. In someinstances, d=0 and f≥0.60. In some instances, d=0 and f≥0.80. In someinstances, d=0 and f≥0.80. In some instances, d=0 and f≥0.60. In someinstances, d=0 and f≥0.40. In some instances, d=0 and f≥0.20. In someinstances, d=0 and e≥2.20. In some instances, d=0 and e≥2.40. In someinstances, d=0 and e≥2.60. In some instances, d=0 and e≥2.80. In someinstances, d=0 and e≤2.80. In some instances, d=0 and e≤2.60. In someinstances, d=0 and e≤2.40. In some instances, d=0 and e≤2.20. It will beunderstood that, in the aforementioned instances, the boundaries off ande can be combined in any variation as above.

In some instances, M¹ can include one or more cations with an averageoxidation state of 4+, i.e., M¹ ₁. M¹ also can include more than onecation with a combined oxidation state of 3+, i.e., M¹ ₁M¹ ₂. M¹ ₁ isselected from Ti, Mn, Zr, Mo, and Ru and may be any combination thereof.M¹ ₂ is selected from Mg, Ca, V, Cr, Fe, Cu, Zn, Al, Sc, Y, Ga, and Zrand may be any combination thereof. A stoichiometric content associatedwith M¹ ₁, i.e., d₁, and a stoichiometric content associated with M¹ ₂,i.e., d₂, equals d (i.e., d₁+d₂=d). In these instances, a+b+c+d₁+d₂=1.Further, in some instances, d₁≥0.1. In some instances, d₁≥0.2. In someinstances, d₁≥0.3. In some instances, d₁≥0.4. In some instances, d₁≤0.1.In some instances, d₁≤0.2. In some instances, d₁≤0.3. In some instances,d₁≤0.4. It will be understood that, in the aforementioned instances, theboundaries of d₁ can be combined in any variation as above.

In some instances, −0.05≤f≤0.10; M¹=Al; 0≤d≤0.05; a+b+c=1; 0<a+b<0.5;and 1.95≤e≤2.6. In further instances, 0.01≤d≤0.03. In still furtherinstances, 0.02≤d≤0.03. In instances where d≠0 (i.e., aluminum ispresent), a distribution of aluminum within each particle may be uniformor may be biased to be proximate to a surface of each particle. Otherdistributions are possible.

In some instances, −0.05≤f≤0.10; d=0; a=0, b+c=1; and 1.9≤e≤2.2.Further, in some instances, 0.0≤f≤0.10. In some instances, 0.0≤f≤0.05.In some instances, 0.01≤f≤0.05 and 0.02≤b≤0.05. In some instances,0.01≤f≤0.05 and b=0.04.

In some variations, this disclosure is directed to a cathode activeprecursor compound, or particles (e.g., a powder) comprising the cathodeactive precursor compound, represented by Formula (IIa):M²O_(g)  (IIa)wherein M²=Co, Mn, Ni, and any combination thereof; and 0.9≤g≤2.6. Insome variations, 0.9≤g≤1.1. In some variations, g=1. In some variations,1.4≤g≤1.6. In some variations, g=1.5. In some variations, 1.9≤g≤2.1. Insome variations, g=2. In some variations, 2.4≤g≤2.6. In some variations,g=2.5.

In some variations, this disclosure is directed to a cathode activecompound, or particles (e.g., a powder) comprising the cathode activecompound, represented by Formula (IIb):Li_(h)M²O_(g)  (IIb)wherein M²=Co, Mn, Ni, and any combination thereof, 0.95≤h≤2, and 2≤g≤3.In some variations, 1≤h≤2. In some variations, 1.20≤h. In somevariations, 1.40≤h. In some variations, 1.60≤h. In some variations,1.80≤h. In some variations, h≤1.8. In some variations, h≤1.6. In somevariations, h≤1.4. In some variations, h≤1.2. In some variations, h≤1.8.Further, in some variations, 2.2≤g. In some variations, 2.4≤g. In somevariations, 2.6≤g. In some variations, 2.8≤g. In some variations, g≤2.8.In some variations, g≤2.6. In some variations, g≤2.4. In somevariations, g≤2.2. It will be understood that the boundaries of h and gcan be combined in any variation as above.

In some variations, this disclosure is directed to a cathode activeprecursor compound, or particles (e.g., a powder) comprising the cathodeactive precursor compound, represented by Formula (IIIa):M³ _(i)M⁴ _(1-i)O_(j)  (IIIa)wherein M³ is selected from Ti, Mn, Zr, Mo, Ru, and any combinationthereof; M⁴ is selected from B, Na, Mg, Ti, Ca, V, Cr, Mn, Fe, Co, Ni,Cu, Zn, Al, Sc, Y, Ga, Zr, Ru, Mo, and any combination thereof; 0≤i≤1;and 0.9≤j≤2.6. In some variations, M³ has an average oxidation state of4+(i.e., tetravalent). In some variations, M⁴ has an average oxidationstate of 3+(i.e., trivalent). In some variations, 0<i<1. In specificvariations, M³ is Mn. In specific variations, M⁴ is Co. In specificvariations, M⁴ is a combination of Co and Mn. In further variations, aproportion of Co is greater than a proportion of Mn in the combinationof Co and Mn.

In some variations, 1.4≤j≤2.1. In some variations, 1.5≤j≤2.0. In somevariations, 1.6≤j≤1.9. In some variations, 0.9≤j≤1.1. In somevariations, j=1. In some variations, 1.4≤j≤1.6. In some variations,j=1.5. In some variations, 1.9≤j≤2.1. In some variations, j=2. In somevariations, 2.4≤j≤2.6. In some variations, j=2.5.

In some variations, this disclosure is directed to a cathode activecompound, or particles (e.g., a powder) comprising the cathode activecompound, represented by Formula (IIIb):(i)[Li₂M³O₃]•(1−i)[LiM⁴O₂]  (IIIb)wherein M³ is one or more cations with an average oxidation state of4+(i.e., tetravalent), M⁴ is one or more cations with an averageoxidation state of 3+ (i.e., trivalent), and 0≤i≤1. In some variations,M³ is selected from Ti, Mn, Zr. Mo, Ru, and a combination thereof. Inspecific variations, M³ is Mn. In some variations, M⁴ is selected fromB, Na, Mg, Ti, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Sc, Y, Ga, Zr, Ru,Mo and a combination thereof. In specific variations, M⁴ is Co. Inspecific variations, M⁴ is a combination of Co and Mn. In furthervariations, a proportion of Co is greater than a proportion of Mn in thecombination of Co and Mn. In variations where M⁴ includes cobalt, cobaltmay be a predominant transition-metal constituent.

In some variations, this disclosure is directed to a cathode activecompound, or particles (e.g., a powder) comprising the cathode activecompound, represented by Formula (IIIc):(i)[Li₂M³O₃]•(1−i)[L_(1-k)M⁴O₂]  (IIIc)wherein M³ is one or more cations with an average oxidation state of4+(i.e., tetravalent), M⁴ is one or more cations, 0≤i≤1, and 0≤k≤1. Insome variations, M³ is selected from Ti, Mn, Zr, Mo, Ru, and acombination thereof. In specific variations, M³ is Mn. In somevariations, M⁴ is selected from B, Na, Mg, Ti, Ca, V, Cr, Mn, Fe, Co,Ni, Cu, Zn, Al, Sc, Y, Ga, Zr, Ru, Mo, and any combination thereof. Inspecific variations, M⁴ is Co. In specific variations, M⁴ is acombination of Co and Mn. In further variations, a proportion of Co isgreater than a proportion of Mn in the combination of Co and Mn. Invariations where M⁴ includes cobalt, cobalt may be a predominanttransition-metal constituent which allows high voltage, and highvolumetric energy density for cathode active materials employed inlithium-ion batteries.

In some variations, 0≤k≤0.16. In some variations, 0≤k≤0.14. In somevariations, 0≤k≤0.12. In some variations, 0≤k≤0.10. In some variations,0≤k≤0.08. In some variations, 0≤k≤0.06. In some variations, 0≤k≤0.04. Insome variations, 0≤k≤0.02. In some variations, k=0.15. In somevariations, k=0.14. In some variations, k=0.13. In some variations,k=0.12. In some variations, k=0.11. In some variations, k=0.10. In somevariations, k=0.09. In some variations, k=0.08. In some variations,k=0.07. In some variations, k=0.06. In some variations, k=0.05. In somevariations, k=0.04. In some variations, k=0.03. In some variations,k=0.02. In some variations, k=0.01.

In some variations, this disclosure is directed to a cathode activeprecursor compound, or particles (e.g., a powder) comprising the cathodeactive precursor compound, represented by Formula (IVa):Co_(1-l)M⁵ _(l)Al_(m)O_(n)  (IVa)wherein M⁵ is B, Na, Mn, Ni, Mg, Ti, Ca, V, Cr, Fe, Cu, Zn, Al, Sc, Y,Ga, Zr, Mo, Ru, and any combination thereof, 0<l<0.50; 0≤m≤0.05; and0.9≤n≤2.6. In some variations, M⁵ is Mn, Ni, and any combinationthereof.

In some variations, 1.4≤n≤2.1. In some variations, 1.5≤n≤2.0. In somevariations, 1.6≤n≤1.9. In some variations, 0.9≤n≤1.1. In somevariations, n=1. In some variations, 1.4≤n≤1.6. In some variations,n=1.5. In some variations, 1.9≤n≤2.1. In some variations, n=2. In somevariations, 2.4≤n≤2.6. In some variations, n=2.5.

In some variations, 0.01≤m≤0.03. In some variations, 0.001≤m≤0.005. Insome variations, 0.002≤m≤0.004. In some variations, m=0.003. In somevariations, 0.02≤m≤0.03. In variations of Formula (IVa) where m #0(i.e., aluminum is present), a distribution of aluminum within theparticle may be uniform or may be biased to be proximate to a surface ofthe particle. Other distributions of aluminum are possible. In somevariations, Al is at least 500 ppm. In some variations, Al is at least750 ppm. In some variations, Al is at least 900 ppm. In some variations,Al is less than or equal to 2000 ppm. In some variations, Al is lessthan or equal to 1500 ppm. In some variations, Al is less than or equalto 1250 ppm. In some variations, Al is approximately 1000 ppm. In anoptional alternative, the compound can be expressed as Co_(1-l)M⁵_(l)O_(n) and Al expressed in ppm.

In some variations, 0.9≤n≤1.1. In some variations, n=1. In somevariations, 1.4≤n≤1.6. In some variations, n=1.5. In some variations,1.9≤n≤2.1. In some variations, n=2. In some variations, 2.4≤n≤2.6. Insome variations, n=2.5. In some variations, 1.4≤n≤2.1. In somevariations, 1.5≤n≤2.0. In some variations, 1.6≤n≤1.9.

In some variations, this disclosure is directed to a cathode activecompound, or particles (e.g., a powder) comprising the cathode activecompound, represented by Formula (IVb):Li_(o)Co_(1-l)M⁵ _(l)Al_(m)O_(n)  (IVb)wherein M⁵ is B, Na, Mn, Ni, Mg, Ti, Ca, V, Cr, Fe, Cu, Zn, Al, Sc, Y,Ga, Zr, Mo, Ru, and any combination thereof; 0.95≤o≤1.10; 0≤l≤0.50;0≤m≤0.05; and 1.95≤n≤2.60. In some variations, M⁵ is Mn, Ni, and anycombination thereof.

In some variations, 0.01≤m≤0.03. In some variations, 0.001≤m≤0.005. Insome variations, 0.002≤m≤0.004. In some variations, m=0.003. In somevariations, 0.02≤n≤m 0.03. In variations of Formula (IVb) where m #0(i.e., aluminum is present), a distribution of aluminum within theparticle may be uniform or may be biased to be proximate to a surface ofthe particle. Other distributions of aluminum are possible. In somevariations, Al is at least 500 ppm. In some variations, Al is at least750 ppm. In some variations, Al is at least 900 ppm. In some variations,Al is less than or equal to 2000 ppm. In some variations, Al is lessthan or equal to 1500 ppm. In some variations, Al is less than or equalto 1250 ppm. In some variations, Al is approximately 1000 ppm. Inadditional variations of Formula (IVb), 1.02≤o≤1.05 and 0.02≤l≤0.05. Infurther variations of Formula (4b), 1.03≤o≤1.05 and l=0.04. It will berecognized that the components as described above can be in anycombination. In some instances, when Al is expressed in ppm, in oneaspect, the compound can be represented as Li_(o)Co_(1-l)M⁵ _(l)O_(n)and the amount of Al can be represented as Al in at least a quantity inppm, as described herein.

The various compounds of Formulae (IIb), (IIIb), (IIIc), and (IVb) caninclude Mn⁴⁺. Without wishing to be limited to any theory or mode ofaction, incorporating Mn⁴⁺ can improve a stability of oxide under highvoltage charging (e.g., 4.5V) and can also help maintain an R ³ mcrystal structure (i.e., the α-NaFeO₂ structure) when transitioningthrough a 4.1-4.3V region (i.e., during charging and discharging).

In some variations, this disclosure is directed to a cathode activeprecursor compound, or particles (e.g., a powder) comprising the cathodeactive precursor compound, represented by Formula (Va):Co_(1-p)Mn_(p)M⁶ _(q)O_(r)  (Va)wherein M⁶ is at least one element selected from the group consisting ofB, Na, Mg, Ti, Ca, V, Cr, Fe, Co, Ni, Cu, Zn, Al, Sc, Y, Ga, Zr, Ru, andMo; 0≤p≤0.30; 0≤q≤0.10; and 0.9≤r≤2.6. In some variations, q=0. In somevariations, M⁶ is Al.

In some variations, 1.4≤r≤2.1. In some variations, 1.5≤r≤2.0. In somevariations, 1.6≤r≤1.9. In some variations, 0.9≤r≤1.1. In somevariations, r=1. In some variations, 1.4≤r≤1.6. In some variations,r=1.5. In some variations, 1.9≤r≤2.1. In some variations, n=r. In somevariations, 2.4≤r≤2.6. In some variations, r=2.5.

In some variations, this disclosure is directed to a cathode activecompound, or particles (e.g., a powder) comprising the cathode activecompound, represented by Formula (Vb):Li_(s)Co_(1-p)Mn_(p)O_(r)  (Vb)wherein 0.95≤s≤1.10, 0≤p≤0.10, and 1.90≤r≤2.20. In some variations,0<p≤0.10. In some variations, 0.98≤s≤1.01. In some variations of Formula(Vb), 0.98≤s≤1.01 and p=0.03. In some variations of Formula (Vb),1.00≤s≤1.05. In some variations, the disclosure is directed to acompound represented by Formula (Vb), wherein 0.95≤s≤1.05 and0.02≤p≤0.05. In a further aspect, the disclosure is directed to acompound represented by Formula (Vb), wherein 0.95≤s≤1.05 and p=0.04. Insome variations, p=0.03. In further variations of Formula (Vb),1.01≤s≤1.05 and 0.02≤p≤0.05. In still further variations of Formula(Vb), 1.01≤s≤1.05 and p=0.04. In some variations of Formula (Vb),1.00<s≤1.10. In other variations of Formula (Vb), 1.00<s≤1.05. In afurther aspect, the disclosure is directed to a compound represented byFormula (Vb), wherein 0.98≤s≤1.01, p=0.03, and r=2.

It will be appreciated that s represents a molar ratio of lithiumcontent to total transition-metal content (i.e., total content of Co andMn). In various aspects, increasing lithium content can increasecapacity, improve stability, increase gravimetric density of particlescomprising the compound, increase particle density, and/or increaseparticle strength of the cathode active material. In various aspects,decreasing lithium content can increase capacity, improve stability,increase gravimetric density of particles comprising the compound,increase particle density, and/or increase particle strength of thecathode active material.

In some variations, the compound of Formula (Vb) may be represented as asolid solution of two phases, i.e., a solid solution of Li₂MnO₃ andLiCoO₂. In these variations, the compound may be described according toFormula (Vc):(p)[Li₂MnO₃]•(1−p)[LiCoO₂]  (Vc)where Mn is a cation with an average oxidation state of 4+(i.e.,tetravalent) and Co is a cation with an average oxidation state of3+(i.e., trivalent). A more compact notation for Formula (Vc) is givenbelow:Li_(1+p)Co_(1-p)Mn_(p)O_(2+p)  (Vd)In Formula (Vd), p can describe both Mn and Co. Due to differingvalences between Mn and Co, the inclusion of Mn may influence a lithiumcontent and an oxygen content of the compound.

Referring back to Formula (Vb), ‘p’ can be 0≤p≤0.10. In such variations,the lithium content can be from 1 to 1.10 (i.e., 1+p), and the oxygencontent can be from 2 to 2.10 (i.e., 2+p). However, the compoundsdisclosed herein have lithium contents and oxygen contents that may varyindependently of p. For example, and without limitation, the lithium andoxygen contents may vary from stoichiometric values due to synthesisconditions deliberately selected by those skilled in the art. As such,subscripts in Formulas (Vc) and (Vd) are not intended as limiting onFormula (Vb), i.e., s is not necessarily equal to 1+p, and r is notnecessarily equal 2+p. It will be appreciated that one or both of thelithium content and the oxygen content of compounds represented byFormula (Vb) can be under-stoichiometric (i.e., s<1+p; r<2+p) orover-stoichiometric (i.e., s>1+l; r>2+p) relative to the stoichiometricvalues of Formula (Vd).

In some variations, the compound of Formula (Vb) may be represented as asolid solution of two phases, i.e., a solid solution of Li₂MnO₃ andLiCoO₂. In these variations, the compound may be described according toFormula (Ve):(t)[Li₂MnO₃]•(1−t)[Li_((1−u))Co_((1−u))Mn_(u)O₂]  (Ve)where Mn is a cation with an average oxidation state of 4+(i.e.,tetravalent) and Co is a cation with an average oxidation state of3+(i.e., trivalent). A unified notation for Formula (Ve) is given below:Li_(1+t−u−tu)Co_((1−t)(1−u))Mn_((t+u−tu))O_(2+t)  (Vf)In Formula (Vf), t and u can describe both Mn and Co. Without wishing tobe held to a particular mechanism or mode of action, because ofdiffering valences between Mn and Co, inclusion of Mn may influencelithium content and oxygen content of the compound.

Comparing Formulas (Vb) and (Vf) shows s=1+t−u−tu, p=t+u−tu, r=2+t. Incompounds represented by Formula V(f), the lithium content can be anyrange described herein for Formula (Vb). In some variations, Li can befrom 0.95 to 1.10. In some variations, oxygen content can be from 2 to2.20.

In other variations, this disclosure is directed to a compound, orparticles (e.g., a powder) comprising a compound, represented by Formula(Vg):Li_(s)Co_(1−p−q)Mn_(p)M⁶ _(q)O_(r)  (Vg)wherein 0.95≤s≤1.30, 0≤p≤0.30, 0≤q≤0.10, and 1.98≤r≤2.04, and M⁶ is atleast one element selected from the group consisting of B, Na, Mg, Ti,Ca, V, Cr, Fe, Co, Ni, Cu, Zn, Al, Sc, Y, Ga, Zr, Ru, and Mo. Thecompound of Formula (Vg) is single phase. The compound can have atrigonal R ³ m crystal structure. In further variations, 0.98≤s≤1.16 and0<p≤0.16. In some variations 0.98≤s≤1.16, 0<p≤0.16, and 0<q≤0.05.

In other variations, this disclosure is directed to a compound, orparticles (e.g., a powder) comprising a compound, represented by Formula(Vh):Li_(s)Co_(1−p−q)Mn_(p)Al_(q)O_(r)  (Vh)wherein 0.95≤s≤1.30, 0≤p≤0.30, 0≤q≤0.10, and 1.98≤r≤2.04. In somevariations, 0.96≤s≤1.04, 0≤p≤0.10, 0≤q≤0.10, and 1.98≤r≤2.04. In somevariations, the compounds represented by Formula (Vh) have 0.98≤s≤1.01,0.02≤p≤0.04, and 0≤q≤0.03. The compound of Formula (Vh) is a singlephase. The compound can have trigonal R ³ m crystal structure.

In some variations, this disclosure is directed to a cathode activeprecursor compound, or particles (e.g., a powder) comprising the cathodeactive precursor compound, represented by Formula (VIa):(v)[M⁷O₂]•(1−v)[Co_(1−σ)M⁸ _(σ)O₂]  (VIa)wherein M⁷ is one or more elements with an average oxidation state of4+(i.e., tetravalent); M⁸ is one or more monovalent, divalent,trivalent, and tetravalent elements; 0.01≤v<1.00, and 0≤σ≤0.05. In somevariations, M⁷ is selected from Mn, Ti, Zr, Ru, and a combinationthereof. In some variations, M⁸ is selected from B, Na, Mg, Ti, Ca, V,Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Sc, Y, Ga, Zr, Ru, Mo and a combinationthereof. In some variations, M⁷ is Mn. In some variations, M⁸ is Al.

In some embodiments, 0.01≤v≤0.50. In some embodiments, 0.01≤v<0.50. Insome embodiments, 0.01≤v≤0.30. In some embodiments, 0.01≤v<0.10. In someembodiments, 0.01≤v<0.05. In some variations, 0<σ≤0.05. In somevariations, 0<σ≤0.03. In some variations, 0<σ≤0.02. In some variations,0<σ≤0.01. In some variations, 0.01≤v<0.05, and 0<σ≤0.05.

In some variations, Al is at least 500 ppm. In some variations, Al is atleast 750 ppm. In some variations, Al is at least 900 ppm. In somevariations, Al is less than or equal to 2000 ppm. In some variations, Alis less than or equal to 1500 ppm. In some variations, Al is less thanor equal to 1250 ppm. In some variations, Al is less than or equal to1000 ppm. In some variations, Al is less than or equal to 900 ppm. Insome variations, Al is less than or equal to 800 ppm. In somevariations, Al is less than or equal to 700 ppm. In some variations, Alis less than or equal to 600 ppm. In some instances, when M⁸ (e.g., Al)is expressed in ppm, in optional variations, the compound can berepresented as (v)[Li₂M⁷O₃]•(1−v)[Li_(α)Co_(w)O₂] and the amount of M⁸can be represented as M⁸ in at least a quantity in ppm, as otherwisedescribed above. In some embodiments, 0.5≤w≤1. In some embodiments,0.8≤w≤1. In some embodiments, 0.96≤w≤1. In some embodiments, 0.99≤w≤1.In some embodiments, w is 1.

In some variations, this disclosure is directed to a cathode activecompound, or particles (e.g., a powder) comprising the cathode activecompound, represented by (VIb):(v)[Li₂M⁷O₃]•(1−v)[Li_(α)Co_(1-σ)M⁸ _(σ)O₂]  (VIb)wherein M⁷ is one or more elements with an average oxidation state of4+(i.e., tetravalent); M⁸ is one or more monovalent, divalent,trivalent, and tetravalent elements; 0.95≤α≤1.05, 0.95≤α≤0.99,0.01≤v<1.00, and 0.5≤w≤1, and 0≤σ≤0.05. In some variations, M⁷ isselected from Mn, Ti, Zr, Ru, and a combination thereof. In somevariations, M⁸ is selected from B, Na, Mg, Ti, Ca, V, Cr, Mn, Fe, Co,Ni, Cu, Zn, Al, Sc, Y, Ga, Zr, Ru, Mo and a combination thereof. In somevariations, M⁷ is Mn. In some variations, M⁸ is Al.

In some embodiments, 0.01≤v≤0.50. In some embodiments, 0.01≤v<0.50. Insome embodiments, 0.01≤v≤0.30. In some embodiments, 0.01≤v<0.10. In someembodiments, 0.01≤v<0.05. In some variations, 0<σ≤0.05. In somevariations, 0 <σ≤0.03. In some variations, 0<σ≤0.02. In some variations,0<σ≤0.01. In some variations, 0.95≤α≤1.05, 0.95≤α<0.99, 0.01≤v<0.05,0.96≤w<1, and 0<σ≤0.05.

In some variations, M⁸ (e.g., Al) is at least 500 ppm. In somevariations, M⁸ (e.g., Al) is at least 750 ppm. In some variations, M⁸(e.g., Al) is at least 900 ppm. In some variations, M⁸ (e.g., Al) isless than or equal to 2000 ppm. In some variations, M⁸ (e.g., Al) isless than or equal to 1500 ppm. In some variations, M⁸ (e.g., Al) isless than or equal to 1250 ppm. In some variations, M⁸ (e.g., Al) isless than or equal to 1000 ppm. In some variations, M (e.g., Al) is lessthan or equal to 900 ppm. In some variations, M⁸ (e.g., Al) is less thanor equal to 800 ppm. In some variations, M⁸ (e.g., Al) is less than orequal to 700 ppm. In some variations, M (e.g., Al) is less than or equalto 600 ppm. In some instances, when M⁸ (e.g., Al) is expressed in ppm,the compound can be represented as (v)[Li₂M⁷O₃]•(1−v)[Li_(α)Co_(w)O₂]and the amount of M⁸ can be represented as M⁸ in at least a quantity inppm, as otherwise described above. In some variations, 0.5≤w≤1. In somevariations, 0.8≤w≤1. In some variations, 0.96≤w≤1. In some variations,0.99≤w≤1. In some variations, w is 1.

In some variations, the disclosure is directed to a cathode activematerial for lithium ion batteries that includes a lithium nickel oxide(LiNiO₂) having one or more tetravalent metals selected from Mn, Ti, Zr,Ge, Sn, and Te and/or one or more divalent metals selected from Mg, Be,Ca, Sr, Ba, Fe, Ni, Cu, and Zn. In these materials, the trivalent Ni ioncan serve as host to supply the capacity. Without wishing to be limitedto any theory or mode of action, a tetravalent ion such as Mn⁴⁺, and adivalent ion such as Mg²⁺, can stabilize the structure and help Ni ionstay trivalent for typical layer LiNiO₂ oxide.

The lithium nickel oxide may also include a stabilizer component,Li₂MeO₃, in which Me is one or more elements selected from Mn, Ti, Ru,and Zr. Without wishing to be limited to any theory or mode of action,Li₂MeO₃ can stabilize a layered crystal structure and improve areversible capability of the lithium nickel oxide in a voltage window ofa lithium-ion cell. Representative examples of Me include Mn, Ti, Ru,Zr, and any combination thereof.

In some variations, this disclosure is directed to a cathode activeprecursor compound, or particles (e.g., a powder) comprising the cathodeactive precursor compound, represented by Formula (VIIa):Ni_(x)M⁹ _(y)M¹⁰ _(z)O_(α)  (VIIa)where M⁹ is selected from Mn, Ti, Zr, Ge, Sn, Te, and any combinationthereof; M¹⁰ is selected from Mg, Be, Ca, Sr, Ba, Fe, Ni, Cu, Zn, andany combination thereof; 0.7<x<1; 0<y<0.3; 0<z<0.3; x+y+z=1; and0.9≤α≤2.6. In some variations of Formula (VIIa), M⁹ is Mn and M¹⁰ is Mg.In some variations of Formula (VIIa), 0.05<y<0.3 and 0.05<z<0.3.

In some variations, 1.4≤α≤2.1. In some variations, 1.5≤α≤2.0. In somevariations, 1.6≤α≤1.9. In some variations, 0.9≤α≤1.1. In somevariations, α=1. In some variations, 1.4≤α≤1.6. In some variations,α=1.5. In some variations, 1.9≤α≤2.1. In some variations, α=2. In somevariations, 2.4≤α≤2.6. In some variations, α=2.5.

In some variations, this disclosure is directed to a cathode activecompound, or particles (e.g., a powder) comprising the cathode activecompound, represented by Formula (VIIb):Li_(β)Ni_(x)M⁹ _(y)M¹⁰ _(z)O₂  (VIIb)where M⁹ is selected from Mn, Ti, Zr, Ge, Sn, Te, and a combinationthereof; M¹⁰ is selected from Mg, Be, Ca, Sr, Ba, Fe, Ni, Cu, Zn, and acombination thereof; 0.9<β<1.1; 0.7<x<1; 0<y<0.3; 0<z<0.3; and x+y+z=1.In some variations of Formula (VIIb), 0.05<y<0.3 and 0.05<z<0.3.

In some variations, this disclosure is directed to a cathode activecompound, or particles (e.g., a powder) comprising the cathode activecompound, represented by Formula (VIIc):Li_(β)Ni_(x)Mn_(y)Mg_(z)O₂  (VIIc)where 0.9<β<1.1; 0.7<x<1; 0<y<0.3; <z<0.3; and x+y+z=1. In somevariations of Formula (VIIc), 0.05<y<0.3 and 0.05<z<0.3.

In compounds of Formula (VIIc), a valence of Mg remains 2+ and a valenceof Mn remains 4+. Again, without wishing to be held to a particulartheory or mode of action, the valence of Mg remains 2+ to stabilize alayered crystal structure and improve electrochemical performance of thecathode active materials represented by Formula (VIIc). As compared toknown cathode formulae, the amount of Ni²⁺ can be reduced to achievecharge balance. Unlike Ni²⁺, which can transition electronically toNi³⁺, Mg²⁺ represents a stable divalent ion in the cathode activematerial. Thus, in order to maintain an average transition-metal valenceof 3+, a presence of Mg²⁺ in the cathode active material biases Ni awayfrom Ni²⁺ to Ni³⁺. Such bias towards Ni³⁺ decreases the availability ofNi²⁺ to occupy a Li⁺ site, which decreases performance of the cathodeactive material.

In some variations, Ni is an active transition metal at a higherstoichiometric amount than in conventional materials. In furthervariations, the active transition metal of Ni is trivalent in thematerial (i.e., 3+). During an electrochemical charge/discharge processin a cell, the redox couple between Ni³⁺/Ni⁴⁺ influences a capacity ofthe cell.

The compounds of Formulae (VIIb) and (VIIc) as disclosed herein haveproperties that are surprisingly improved over properties of knowncompositions.

In some variations, this disclosure is directed to a cathode activeprecursor compound, or particles (e.g., a powder) comprising the cathodeactive precursor compound, represented by Formula (VIIIa):M¹¹ _(γ)Ni_((1−γ)δ)M¹² _((1−γ)ε)M¹³ _((1−γ)ζ)O_(η)  (VIIIa)where M¹¹ is selected from Mn, Ti, Ru, Zr, and any combination thereof;M² is selected from Mn, Ti, Zr, Ge, Sn, Te, and any combination thereof;M¹³ is selected from Mg, Be, Ca, Sr, Ba, Fe, Ni, Cu, Zn, and anycombination thereof; 0≤γ≤0.3; 0.7<δ<1; 0<ε<0.3; 0≤ζ<0.3; δ+ε+ζ=1; and0.9≤η≤2.6.

In some variations of Formula (VIIIa), 0.05<ε<0.3 and 0.05<ζ<0.3. Insome variations, 1.4≤η≤2.1. In some variations, 1.5≤η≤2.0. In somevariations, 1.6≤η1.9. In some variations, 0.9≤η1.1. In some variations,η=1. In some variations, 1.4≤η≤1.6. In some variations, η=1.5. In somevariations, 1.9≤η≤2.1. In some variations, η=2. In some variations,2.4≤η≤2.6. In some variations, η=2.5.

In some variations, this disclosure is directed to a cathode activecompound, or particles (e.g., a powder) comprising the cathode activecompound, represented by Formula (VIIIb):γLi₂M¹¹O₃•(1−γ)Li_(θ)Ni_(δ)M¹² _(ε)M¹³ _(ζ)O₂  (VIIIb)In Formula (VIIIb), Li_(θ)Ni_(δ)M¹² _(ε)M¹³ _(ζ)O₂ serves as the activecomponent and Li₂M¹¹O₃ serves as the stabilizer component. The compoundof Formula (VIIIb) corresponds to integrated or composite oxidematerial. A ratio of the components is governed by γ, which rangesaccording to 0≤γ≤0.3. For the Li₂M¹¹O₃ stabilizer component, M¹¹ isselected from Mn, Ti, Ru, Zr, and any combination thereof. For theLi_(θ)Ni_(δ)M¹² _(ε)M¹³ _(ζ)O₂ active component, M¹² is selected fromMn, Ti, Zr, Ge, Sn, Te, and any combination thereof; M¹³ is selectedfrom Mg, Be, Ca, Sr, Ba, Fe, Ni, Cu, Zn, and any combination thereof;0.9<θ<1.1; 0.7<δ<1; 0<ε<0.3; 0<ζ<0.3; and δ+ε+ζ=1. In some variations ofFormula (VIIIb), 0.05<ε<0.3 and 0.05<ζ<0.3.

In some variations, this disclosure is directed to a cathode activeprecursor compound, or particles (e.g., a powder) comprising the cathodeactive precursor compound, represented by Formula (IXa):(v)[M⁷O₂]•(1−v)[Co_(1-σ)M⁸ _(σ)O₂]  (IXa)wherein M⁷ is one or more elements with an average oxidation state of4+(i.e., tetravalent); M⁸ is one or more monovalent, divalent,trivalent, and tetravalent elements; 0.01≤v<1.00, and 0.5≤ and 0≤σ≤0.05.In some variations, M⁷ is selected from Mn, Ti, Zr, Ru, and acombination thereof. In some variations, M⁸ is selected from B, Na, Mg,Ti, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Sc, Y, Ga, Zr, Ru, Mo and acombination thereof. In some variations, M⁷ is Mn. In some variations,M⁸ is Al.

In some embodiments, 0.01≤v≤0.50. In some embodiments, 0.01≤v<0.50. Insome embodiments, 0.01≤v≤0.30. In some embodiments, 0.01≤v<0.10. In someembodiments, 0.01≤v<0.05. In some variations, 0≤σ≤0.05. In somevariations, 0<σ≤0.05. In some variations, 0<σ≤0.03. In some variations,0<σ≤0.02. In some variations, 0<σ≤0.01. In some variations, 0.01≤v<0.05and 0<σ≤0.05.

In some variations, Al is at least 500 ppm. In some variations, Al is atleast 750 ppm. In some variations, Al is at least 900 ppm. In somevariations, Al is less than or equal to 2000 ppm. In some variations, Alis less than or equal to 1500 ppm. In some variations, Al is less thanor equal to 1250 ppm. In some variations, Al is less than or equal to1000 ppm. In some variations, Al is less than or equal to 900 ppm. Insome variations, Al is less than or equal to 800 ppm. In somevariations, Al is less than or equal to 700 ppm. In some variations, Alis less than or equal to 600 ppm. In some instances, when M⁸ (e.g., Al)is expressed in ppm, in optional variations, the compound can berepresented as (v)[Li₂M⁷O₃]•(1−v)[Li_(α)Co_(w)O₂] and the amount of M⁸can be represented as M⁸ in at least a quantity in ppm, as otherwisedescribed above. In some embodiments, 0.5≤w≤1. In some embodiments,0.8≤w≤1. In some embodiments, 0.96≤w≤1. In some embodiments, 0.99≤w≤1.In some embodiments, w is 1.

In some variations, this disclosure is directed to a cathode activecompound, or particles (e.g., a powder) comprising the cathode activecompound, represented by Formula (IXb):(v)[Li₂M⁷O₃]•(1−v)[Li_(α)Co_(1-σ)M⁸ _(σ)O₂]  (IXb)wherein M⁷ is one or more elements with an average oxidation state of 4+(i.e., tetravalent); M⁸ is one or more monovalent, divalent, trivalent,and tetravalent elements; 0.95≤α≤1.05, 0.95≤α<0.99, 0.01≤v<1.00, and0.5≤w≤1, and 0≤σ≤0.05. In some variations, M⁷ is selected from Mn, Ti,Zr, Ru, and a combination thereof. In some variations, M⁷ is selectedfrom Mn, Ti, Zr, and Ru. In some variations, M⁸ is selected from B, Na,Mg, Ti, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Sc, Y, Ga, Zr, Ru, Mo anda combination thereof. In some variations, M⁸ is selected from B, Na,Mg, Ti, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Sc, Y, Ga, Zr, Ru, andMo. In some variations, M⁷ is Mn. In some variations, M⁸ is Al.

In some embodiments, 0.01≤v≤0.50. In some embodiments, 0.01≤v<0.50. Insome embodiments, 0.01≤v≤0.30. In some embodiments, 0.01≤v<0.10. In someembodiments, 0.01≤v<0.05. In some variations, 0≤σ≤0.05. In somevariations, 0<σ≤0.05. In some variations, 0<σ≤0.03. In some variations,0<σ≤0.02. In some variations, 0<σ≤0.01. In some variations, 0.95≤α≤1.05,0.95≤α<0.99, 0.01≤v<0.05, 0.96≤w<1, and 0<σ≤0.05.

In some variations, M⁸ (e.g., Al) is at least 500 ppm. In somevariations, M⁸ (e.g., Al) is at least 750 ppm. In some variations, M⁸(e.g., Al) is at least 900 ppm. In some variations, M⁸ (e.g., Al) isless than or equal to 2000 ppm. In some variations, M⁸ (e.g., Al) isless than or equal to 1500 ppm. In some variations, M⁸ (e.g., Al) isless than or equal to 1250 ppm. In some variations, M⁸ (e.g., Al) isless than or equal to 1000 ppm. In some variations, M⁸ (e.g., Al) isless than or equal to 900 ppm. In some variations, M⁸ (e.g., Al) is lessthan or equal to 800 ppm. In some variations, M⁸ (e.g., Al) is less thanor equal to 700 ppm. In some variations, M⁸ (e.g., Al) is less than orequal to 600 ppm. In some instances, when M⁸ (e.g., Al) is expressed inppm, the compound can be represented as(v)[Li₂M⁷O₃]•(1−v)[Li_(α)Co_(w)O₂] and the amount of M⁸ can berepresented as M⁸ in at least a quantity in ppm, as otherwise describedabove. In some variations, 0.5<w<1. In some variations, 0.8<w<1. In somevariations, 0.96<w<1. In some variations, 0.99<w<1. In some variations,w is 1.

In some variations, this disclosure is directed to a cathode activecompound, or particles (e.g., a powder) comprising the cathode activecompound, represented by Formula (X):Li_(α)Co_(1−x−y)M_(y)Mn_(x)O_(δ)  (X)wherein 0.95≤α≤1.30, 0.95≤α≤1.05, 0<x≤0.30, 0≤y≤0.10, and 1.98≤δ≤2.04,and M is at least one element selected from the group consisting of B,Na, Mg, Ti, Ca, V, Cr, Fe, Co, Ni, Cu, Zn, Al, Sc, Y, Ga, Zr, Ru, andMo. The compound of Formula (VII) is single phase. The compound can havea trigonal R ³ m crystal structure. In further variations, 0.98≤α≤1.16and 0<x≤0.16. In some variations 0.98≤α≤1.16, 0<x≤0.16, 0<y≤0.05,1.98≤δ≤2.04.

In some variations, this disclosure is directed to a cathode activecompound, or particles (e.g., a powder) comprising the cathode activecompound, represented by Formula (XI):Li_(α)Co_(1−x−y)Al_(y)Mn_(x)O_(δ)  (XI)wherein 0.95≤α≤1.05, 0.95≤α≤1.05, 0<x<0.30, 0≤y≤0.10, and 1.98≤δ≤2.04.In some variations, 0.96≤α≤1.04, 0<x≤0.10, 0≤y≤0.10, and 1.98≤δ≤2.04. Insome variations, the compounds represented by Formula (XI) have0.98≤α≤1.01, 0.02≤x≤0.04, 0≤y≤0.03, and 1.98≤δ≤2.04. The compound ofFormula (XI) is a single phase. The compound can have trigonal R ³ mcrystal structure.

In other instances, the compounds represented by Formulae (X) and (XI),in any combination of variables described above, have 0.95≤α. In someinstances, α≤1.05. In some instances, α≤1.04. In some instances, α≤1.03.In some instances, α≤1.02. In some instances, α≤1.01. In some instances,α≤1.00. In some instances, α≤0.99. In some instances, α≤0.98. In someinstances, 0.5≤α≤0.98. In some instances, 0.95≤α≤0.99. In someinstances, 0.95≤α≤1.00. In some instances, 0.95≤α≤1.01. In someinstances, 0.95≤α≤1.02. In some instances, 0.95≤α≤1.03. In someinstances, 0.95≤α≤1.04. In some instances, the compounds represented byFormulae (X) and (XI) have α>1+x. In some instances, the compoundsrepresented by Formulae (X) and (XI) have α>1+x. In some instances,α<1+x. As such, a in Formulae (X) and (XI) can deviate from α==1+x,which may be associated with a solid-solution between Li₂MnO₃ and(1−x)LiCo_(1−y)M_(y)O₂. This solid solution can be represented byxLi₂MnO₃•(1−x)LiCo_(1−y)M_(y)O₂, and xLi₂MnO₃•(1−x)Li₁−yCo_(1−y)M_(y)O₂,or in compact notation, Li_(1+x)Co_(1−x−y+xy)M_((1−x))*_(y)Mn_(x)O_(2+x)or Li_(1+x−y+xy)Co_(1−x−y+xy)M_((1−x)*y)Mn_(x)O_(2+x).

Methods of Making the Cathode Active Material

The disclosure is further directed to methods of making the cathodeactive material. The coatings of oxide mixtures or complex oxides areprepared by mixing a cathode active compound particles with a solutionmixture that contains the precursors of the metals that are found in thecoatings. After drying, the mixture is calcined at elevated temperaturesto decompose the precursors into oxides or to promote formation of thecomplex oxides on the cathode active compound material. The coatedcathode active material is then tested as cathode in coin cells that usea Li foil anode, a separator, and flooded electrolyte solution.

In certain variations, a wet impregnation method was used to form anoxide (e.g. Al₂O₃, ZrO₂, or mixture) coating over a particular cathodeactive material. A predetermined amount of the cathode active materialwas weighed out into a glass beaker.

In some variations, to form Al₂O₃ coating, an amount of aluminumprecursor needed for the desired amount of coating (e.g., 0.5 wt. %) wascalculated based on the weighed amount of base powder. The aluminumprecursor included various aluminum salts such as aluminum nitrate,aluminum acetate, or other aluminum salts, which are soluble in water oralcohol. The aluminum precursor was dissolved in a small amount of wateror alcohol to form a first clear solution. A desired amount of lithiumprecursor was calculated using a molar ratio of Li to Al between 0.25and 1.05. The lithium precursor used was lithium hydroxide, lithiumnitrate, lithium acetate, or other lithium salts soluble in water oralcohol. The desired amount of lithium precursor was dissolved in asmall amount of water or alcohol to form a second clear solution. Thefirst and second clear solutions were mixed together. This mixedsolution was then added drop-wise to the base powder while stirring. Thevolume of solution added was such that the base powder becameincipiently wet but not watery (i.e., exhibited a damp consistency).After drying at 50-80° C., the dried base powder was then heat-treatedto 500° C. for 4 h in stagnant air. The pH of the first clear solution(i.e., the aluminum solution) can also be varied to improve coatingproperties such as coating density and uniformity.

In some variations, zirconium precursor includes various zirconiumsalts, such as zirconium acetate, may be used to form ZrO₂ coating.

In some variations, aluminum precursor including various aluminum salts,such as aluminum nitrate, aluminum acetate, and zirconium precursorincludes various zirconium salts, such as zirconium acetate, may be usedto form a mixture of Al₂O₃ and ZrO₂.

In some variations, aluminum precursor including various aluminum salts,such as aluminum nitrate, aluminum acetate, and lanthanum precursorincluding lanthanum salts, such as lanthanum nitrates may be used toform a mixture of Al₂O₃ and La₂O₃.

In some variations, aluminum precursor including various aluminum salts,such as aluminum nitrate, aluminum acetate, and zinc precursor includesvarious zinc salts, such as zinc nitrate, may be used to form a complexoxide ZnAl₂O₄.

In a dry processing, a predetermined amount of cathode active compoundparticles (e.g. Li(Co_(0.97)Mn_(0.03))O₂) was weighed out and pouredinto a dry coater (Nobilta, NOB-130, Hosokawa Micron Ltd). Next, thepowder was weighed out according to a desired amount of coating on thepredetermined base powder (e.g., 0.1 wt. %). The weighed powder waspoured into the dry coater. For a 0.1 wt. % coating, 0.5 g of oxide(e.g. Al₂O₃, ZrO₂, or mixture) was mixed thoroughly with 500 g of basepowder. The speed was controlled at 4000 rpm. After 5 min, anoxide-coated base powder was formed.

Cathode Disk

In some variations, the cathode disks can be formed from the coatedpowder. A ball mill may be used to grind powder into finer powder. Thedensity of the cathode disk may increase by reducing the size of thepowder.

The porosity of the cathode may affect the performance of anelectrochemical cell. A hydraulic press may be used to compact powder toobtain a cathode disk of desired thickness and density during coldpressing. For example, the coated cathode active material was placed ina die that can be compressed up to 5000 lbs. The press includes twoplates that are hydraulically forced together to create a pressure.

Testing Methods

The cathode disks were assembled into button cell (coin cell) batterieswith a Li disk anode, a Celgard 2325 separator (25 μm thick), and theelectrolyte consisting of 1.2 M LiPF6 in ethyl carbonate (EC) and ethylmethyl carbonate (EMC) (EC:EMC=3:7 w/w). Galvanostatic charge/dischargecycling was conducted in the 3.0-4.5 V range at 25° C. The testprocedure includes three formation cycles at a ˜C/5 rate with the 1 Ccapacity assumed to be 185 mAh/g, followed by aging cycles at a C/5 ratewith the 1 C capacity calculated based on the third cycle dischargecapacity. The batteries are aged for 30 to 50 cycles.

An electrochemical tester (e.g. Maccor 4200) provides a user with avariety of options in testing of batteries. Multiple channels can beplugged into the electrochemical tester to allow for multiple batteriesto be tested simultaneously. These tests allow the user to measureparameters of the batteries, such as voltage, current, impedance, andcapacity, to fully understand the effectiveness of the electrochemicalcell being tested. The tester can be attached to a computer to obtaindigital testing values.

EXAMPLES

The following examples are for illustration purposes only. It will beapparent to those skilled in the art that many modifications, both tomaterials and methods, may be practiced without departing from the scopeof the disclosure.

Example 1: Oxide Mixture of Al₂O₃ and ZrO₂ Coating vs Al₂O₃ Coating andZrO₂ Coating

Although ZrO₂ has been used as coatings for lithium (Li)-ion batteriescathodes, a mixture of Al2O3 and ZrO2 has not been used as coatings forbattery cathode materials.

The mixture coatings were applied to three molar percent manganese (Mn)to substitute cobalt (Co) in LiCoO₂ (Li(Co_(0.97)Mn_(0.03))O₂). Thepreparation method included mixing of the cathode active compoundparticles with a dilute acetic acid aqueous solution containingzirconium acetate and aluminum nitrate. The preparation method alsoincluded drying the resulting wet powder at 80° C. overnight, andcalcining the dried powder at 450° C. for four hours in stagnant air. Asa result, the particles were coated with a mixture of Al₂O₃ and ZrO₂.The cathode active material was used to form a cathode in a coin cellagainst Li foil anode.

The coatings including several ratios of the mixture of the Al₂O₃ andZrO₂ were prepared and tested. Tests were performed by the disclosedmethods to determine discharge capacity, average voltage, dischargeenergy, and energy retention of the battery cell.

The electrochemical performance of the cathode was compared with that ofthe uncoated cathode active compound particles alone, Al₂O₃ coatedcathode active compound particles, and ZrO₂ coated cathode activecompound particles. The composition of coatings is shown in Table 1.

TABLE 1 Coating compositions of Al₂O₃ and ZrO₂ Metal content Al₂O₃:ZrO₂in coating Coating type molar ratio Al, ppm Zr, ppm Al₂O₃ 1.00 0.00 2650 Mixture of Al₂O₃ and ZrO₂ 0.287 0.713 265 1111 Mixture of Al₂O₃ andZrO₂ 0.091 0.909 66 1111 Mixture of Al₂O₃ and ZrO₂ 0.092 0.908 133 2221ZrO₂ 0.00 1.00 0 2221

As shown in Table 1, a first mixture of Al₂O₃ and ZrO₂ had a molar ratioof 0.287 to 0.713 for Al₂O₃ to ZrO₂, which has a value of 0.403. Thecoating formed from the first mixture included 265 ppm aluminum and 1111ppm zirconium. A second mixture of Al₂O₃ and ZrO₂ had a molar ratio of0.091 to 0.909 for Al₂O₃ to ZrO₂, which has a value of 0.100. Thecoating formed from the second mixture included 66 ppm aluminum and 1111ppm zirconium. A third mixture of Al₂O₃ and ZrO₂ had a molar ratio of0.092 to 0.908 for Al₂O₃ to ZrO₂, which has a value of 0.101. Thecoating formed from the third mixture included 133 ppm aluminum and 2221ppm zirconium.

FIG. 3 is a plot of discharge capacity versus cycle count for cathodeactive materials including a mixture of Al₂O₃ and ZrO₂ coating onLi(Co_(0.97)Mn_(0.03))O₂ compared with Al₂O₃ coating or ZrO₂ coating onLi(Co_(0.97)Mn_(0.03))O₂, according to an illustrative embodiment. FIG.3 illustrates the effect of a mixture of Al₂O₃ and ZrO₂ coating on thedischarge capacity of a battery. As shown, the ZrO₂ coating provides afirst-cycle discharge capacity of 188 mAh/g, but loses capacity fasterthan the Al₂O₃ coating. In other words, the Al₂O₃ coating is more stablethan the ZrO₂ coating, but starts with a lower first-cycle dischargecapacity of 186 mAh/g than the ZrO₂ coating.

As shown, the second mixture of Al₂O₃ and ZrO₂ coating including 1111ppm Zr and 66 ppm Al provides a first-cycle discharge capacity of about186 mAh/g, and stabilizes the discharge capacity of the battery bydemonstrating a less steep slope for the curve of discharge capacityversus cycle count such that the discharge capacity drops to about 179mAh/g, slightly more than that of the ZrO₂ coating. However, the firstmixture of Al₂O₃ and ZrO₂ coating including 1111 ppm Zr and 265 ppm Aldecreases the discharge capacity to about 184.5 mAh/g, but stabilizesthe capacity of the battery with a less steep slope such that thedischarge capacity drops to about 177 mAh/g after 26 cycles, which islower than that of the ZrO₂ coating. Also, the third mixture of Al₂O₃and ZrO₂ coating including 2221 ppm Zr and 133 ppm Al has a similarcapacity of 186 mAh/g to Al₂O₃ coating, but does not stabilize thedischarge capacity of the battery such that the discharge capacity dropsto about 177 mAh/g after 26 cycles, which is lower than that of the ZrO₂coating. As such, the second mixture of Al₂O₃ and ZrO₂ coating including1111 ppm Zr and 66 ppm Al provides the surprising result of achievingboth enhanced discharge capacity and improved stability over cycles.

FIG. 4 is a plot of average voltage versus cycle count for cathodeactive materials including a mixture of Al₂O₃ and ZrO₂ coating onLi(Co_(0.97)Mn_(0.03))O₂ compared with Al₂O₃ coating or ZrO₂ coating onLi(Co_(0.97)Mn_(0.03))O₂, according to an illustrative embodiment. Asshown in FIG. 4 , the ZrO₂ coating provides a boost to the averagevoltage up to about 4.04 V after 5 cycles, but does not sustain goodretention, as shown by a relatively steep slope such that the voltagedrops to 3.98 V after 26 cycles.

The first mixture of Al₂O₃ and ZrO₂ coating including 1111 ppm Zr and265 ppm Al reduces the slope of the curve of average voltage vs. cyclecount and thus increases the energy retention. The first mixture ofAl₂O₃ and ZrO₂ coating provides an average voltage of about 4.01 V after4 cycles, which is lower than that of ZrO₂ coating and close to that ofAl₂O₃ coating for the same cycles.

The third mixture of Al₂O₃ and ZrO₂ coating including 2221 ppm Zr and133 ppm Al provides a boost to the average voltage of about 4.03 V after4 cycles, but the voltage decreases to 3.98 after 26 cycles, which doesnot improve the energy retention over the ZrO₂.

The second mixture of Al₂O₃ and ZrO₂ coating including 1111 ppm Zr and66 ppm Al) provides a boost to the average voltage up to about 4.04 Vafter 5 cycles, and also reduces the slope of the curve of averagevoltage vs. cycle count such that the voltage drops to about 4.00 after26 cycles, which thus increases the energy retention to be higher thanthat of the ZrO₂ coating. As such, the second mixture of Al₂O₃ and ZrO₂of the coating including 1111 ppm Zr and 66 ppm Al provides thesurprising result of achieving both enhanced average voltage andimproved energy retention.

FIG. 5 is a plot of discharge energy versus cycle count for cathodeactive materials including a mixture of Al₂O₃ and ZrO₂ coating onLi(Co_(0.97)Mn_(0.03))O₂ compared with Al₂O₃ coating or ZrO₂ coating onLi(Co_(0.97)Mn_(0.03))O₂, according to an illustrative embodiment. Thedischarge capacity and average voltage are combined to define thedischarge energy (Wh/kg) of a battery. As shown in FIG. 5 , the ZrO₂coating provides increased discharge energy in comparison to the Al₂O₃coating. However, the ZrO₂ alone cannot sustain the discharge energywithout the addition of Al₂O₃ (e.g. the mixture including 1111 ppm Zrand 66 ppm Al).

FIG. 6 is a plot of energy retention versus cycle count for cathodeactive materials including a mixture of Al₂O₃ and ZrO₂ coating onLi(Co_(0.97)Mn_(0.03))O₂ compared with Al₂O₃ coating or ZrO₂ coating onLi(Co_(0.97)Mn_(0.03))O₂, according to an illustrative embodiment. Theenergy retention is defined as the normalized discharge energy withrespect the discharge energy after 4 cycles. The energy retentionclearly shows the effects of stability of the mixture of Al₂O₃ and ZrO₂coating on Li(Co_(0.97)Mn_(0.03))O₂ over the individual oxide coatings.

As shown, only the mixture including a small amount of Al₂O₃ (e.g. 66ppm) helps stabilize the ZrO₂.

FIG. 7 is a phase diagram of Al₂O₃ and ZrO₂ from Powder Metall. Mt.Ceram., Vol. 33, 1994, p 486-490. As shown in FIG. 7 , the oxides Al₂O₃and ZrO₂ do not combine to form a ternary oxide. Instead, the oxidesAl₂O₃ and ZrO₂ maintain their individual oxide phases and demonstrate anegligible solubility in each other. However, a more recent publication[A. T. Ravichandran et al., Superlattices and Microstructures, 75 (2014)533-542] revealed that 2 to 10 at % Al can be doped into tetragonal ZrO₂nano-powders by solution combustion method using glycine as the fuel ina preheated furnace around 500° C., which reduces the ZrO₂ crystallite'ssize and stabilizes the ZrO₂ tetragonal phase.

Example 2: Oxide Mixture of Al₂O₃ and La₂O₃ Coating

The mixture including Al₂O₃ and La₂O₃ were applied to theLi(Co_(0.97)Mn_(0.03))O₂ cathode active compound particles. The mixtureon Li(Co_(0.97)Mn_(0.03))O₂ were prepared by mixing the cathode activecompound particles with aqueous mixture solution of aluminum andlanthanum nitrates, followed by drying at 80° C. overnight and calciningat 450° C. for four hours in air. As a result, the particles were coatedwith a mixture of Al₂O₃ and La₂O₃. The cathode active material used toform a cathode in a coin cell against Li foil anode. The coatingsincluding several ratios of the mixture of the Al₂O₃ and La₂O₃ wereprepared. The coin cells or battery cells were tested to determine theelectrochemical performance of the cathode.

The electrochemical performance of the cathode is compared with that ofthe cathode active compound particles alone, and cathode active compoundparticles coated with Al₂O₃ alone. The composition of coatings is shownin Table 2.

TABLE 2 Coating compositions of Al₂O₃ and La₂O₃ Metal contentAl₂O₃:La₂O₃ in coating Coating type molar ratio Al, ppm La, ppm Al₂O₃ 10 265 0 Mixture of Al₂O₃ and La₂O₃ 1 1 63 325 Mixture of Al₂O₃ and La₂O₃1 1 126 649 Mixture of Al₂O₃ and La₂O₃ 1 1 252 1296

As shown in Table 2, a first mixture of Al₂O₃ and La₂O₃ had 63 ppm Aland 325 ppm La. A second mixture of Al₂O₃ and La₂O₃ included 126 ppm Aland 649 ppm La. A third mixture of Al₂O₃ and La₂O₃ included 252 ppm Aland 1296 ppm La. The first, second and third mixtures have about thesame molar ratio 1:1 for La₂O₃ to Al₂O₃. Also, the first, second andthird mixtures have Al less than 265 ppm of the Al₂O₃ coating.

FIGS. 8-11 reveal a significant enhancement in the electrochemicalperformance of the oxide mixture coating over the Al₂O₃ coating onLi(Co_(0.97)Mn_(0.03))O₂, including increased discharge capacity andincreased average discharge capacity, increased discharge energyassociated with increased discharge capacity and average dischargecapacity, and enhanced energy retention. Variations in the level ofmixture coatings on Li(Co_(0.97)Mn_(0.03))O₂ particles do not seem toaffect the cathode electrochemical performance much as long as the molarratio remains unchanged.

FIG. 8 is a plot of discharge capacity versus cycle count for cathodeactive materials including a mixture of Al₂O₃ and La₂O₃ coating onLi(Co_(0.97)Mn_(0.03))O₂ with different loadings at 1:1 molar ratio ofLa₂O₃ to Al₂O₃ compared with uncoated Li(Co_(0.97)Mn_(0.03))O₂ and Al₂O₃coating on Li(Co_(0.97)Mn_(0.03))O₂, according to an illustrativeembodiment. As shown in FIG. 8 , all the three mixture coatingsincluding 325 ppm La, 649 ppm La, and 1296 ppm La reveal a dischargecapacity of about 186 mAh/g after 5 cycles, which is higher than that ofthe Al₂O₃ coating, and also higher than that of the uncoated cathodeactive compound particles. Also, the mixture coatings provide adischarge capacity of about 178 mAh/g after 30 cycles, which is higherthan that of the Al₂O₃ coating and that of the uncoated cathode activecompound particles.

FIG. 9 is a plot of average discharge voltage versus cycle count forcathode active materials including a mixture of Al₂O₃ and La₂O₃ coatingon Li(Co_(0.97)Mn_(0.03))O₂ with different loadings at 1:1 molar ratioof La₂O₃ to Al₂O₃ compared with uncoated Li(Co_(0.97)Mn_(0.03))O₂ andAl₂O₃ coating on Li(Co_(0.97)Mn_(0.03))O₂, according to an illustrativeembodiment. FIG. 10 is a plot of discharge energy versus cycle count forcathode active materials including a mixture of Al₂O₃ and La₂O₃ coatingon Li(Co_(0.97)Mn_(0.03))O₂ with different loadings at 1:1 molar ratioof La₂O₃ to Al₂O₃ compared with uncoated Li(Co_(0.97)Mn_(0.03))O₂ andAl₂O₃ coating on Li(Co_(0.97)Mn_(0.03))O₂, according to an illustrativeembodiment. FIG. 11 is a plot of energy retention versus cycle count forcathode active materials including a mixture of Al₂O₃ and La₂O₃ coatingon Li(Co_(0.97)Mn_(0.03))O₂ with different loadings at 1:1 molar ratioof La₂O₃ to Al₂O₃ compared with uncoated Li(Co_(0.97)Mn_(0.03))O₂ andAl₂O₃ coating on Li(Co_(0.97)Mn_(0.03))O₂, according to an illustrativeembodiment. As shown in FIGS. 9-11 , all the first, second, and thirdmixtures reveal improved performance over the Al₂O₃ coating, similar tothat shown in FIG. 8 .

FIG. 12 is a phase diagram of Al₂O₃ and La₂O₃(J. Alloys Compd., Vol.179, 1992, p 259-28). As shown in FIG. 12 , the Al₂O₃ and La₂O₃ oxidesmay combine to form a Perovskite phase, e.g. LaAlO₃, at hightemperatures. The LaAlO₃ has the same type of crystal structure asCaTiO₃, which is known as the Perovskite structure. The Perovskite phasemay also be formed at lower temperatures when the Al₂O₃ and La₂O₃ are innanoparticles forms and mixed at atomic scales, with amount increasingwith the molar ratio of La:Al. (J. Phys. Chem. C2015, 119, 25053-25062).However, it is difficult to identify the perovskite phase in thesecoatings by XRD, as the coating quantity is too low to warrant detectionof the coating phases.

Example 3: Complex Oxide Coating of ZnAl₂O₄

Zinc oxide (ZnO) was investigated as coatings for Li-ion batterycathodes, particularly for the Co-rich cathodes, which was shown toimprove the cathode performance to certain extent. However, there are noliterature investigations used a complex oxide ZnAl₂O₄, a combination ofzinc oxide and aluminum oxide in a spinel structure, as coating forCo-rich cathodes.

The complex oxide ZnAl₂O₄ was used as a coating applied ontoCo-containing cathode material, Li(Co_(0.97)Mn_(0.03))O₂. The coatingwas prepared by mixing the cathode active compound particles with anaqueous mixture solution of Zn and Al nitrates at Zn to Al molar ratioof 1:2, followed by drying at 80° C. and calcining at 700° C. for fourhours in air. As a result, the particles were coated with a complexoxide ZnAl₂O₄. The cathode active compound material was used to form acathode in a coin cell against Li foil anode. The tests were performedto evaluate the electrochemical performance of the coating.

FIGS. 13-16 illustrate the improvement of the complex oxide coating overAl₂O₃ coating on Li(Co_(0.97)Mn_(0.03))O₂. Compared to the Al₂O₃coating, the complex oxide ZnAl₂O₄ coating increases not only dischargecapacity, but also average discharge voltage, leading to the increaseddischarge energy.

FIG. 13 is a plot of discharge capacity versus cycle count for cathodeactive materials including the complex oxide ZnAl₂O₄ coating onLi(Co_(0.97)Mn_(0.03))O₂ compared with uncoated Li(Co_(0.97)Mn_(0.03))O₂and Al₂O₃ coating on Li(Co_(0.97)Mn_(0.03))O₂, according to anillustrative embodiment. As shown in FIG. 13 , the complex oxide ZnAl₂O₄coating provides a boost to the discharge capacity to about 187 mAh/gafter 1 cycle, which is higher than about 184 mAh/g for the Al₂O₃coating. The complex oxide ZnAl₂O₄ coating provides a boost to thedischarge capacity to about 180 mAh/g after 30 cycles, which is higherthan about 176 mAh/g for the Al₂O₃ coating after 30 cycles.

FIG. 14 is a plot of average discharge voltage versus cycle count forcathode active materials including the complex oxide ZnAl₂O₄ coating onLi(Co_(0.97)Mn_(0.03))O₂ compared with uncoated Li(Co_(0.97)Mn_(0.03))O₂and Al₂O₃ coating on Li(Co_(0.97)Mn_(0.03))O₂, according to anillustrative embodiment. As shown in FIG. 14 , the complex oxide ZnAl₂O₄coating provides a boost to the average voltage to about 4.03 V after 4cycles, which is higher than about 4.0 V for the Al₂O₃ coating. Also,the complex oxide ZnAl₂O₄ coating provides a boost to the averagevoltage to about 4.00 V after 30 cycles, which is higher than about 3.95V for the Al₂O₃ coating.

FIG. 15 is a plot of discharge energy versus cycle count for cathodeactive materials including the complex oxide ZnAl₂O₄ coating onLi(Co_(0.97)Mn_(0.03))O₂ compared with uncoated Li(Co_(0.97)Mn_(0.03))O₂and Al₂O₃ coating on Li(Co_(0.97)Mn_(0.03))O₂, according to anillustrative embodiment. As shown in FIG. 15 , the complex oxide ZnAl₂O₄coating provides a boost to the discharge energy to about 755 Wh/kgafter 4 cycles, which is higher than about 735 Wh/kg for the Al₂O₃coating. Also, the complex oxide ZnAl₂O₄ coating provides a boost to thedischarge energy to about 725 Wh/kg after 30 cycles, which is higherthan about 695 Wh/kg for the Al₂O₃ coating. The cathode with the complexoxide ZnAl₂O₄ coating maintains higher discharge energy up to 30 cycles,as shown in FIG. 15 .

FIG. 16 is a plot of energy retention versus cycle count for cathodeactive materials including the complex oxide ZnAl₂O₄ coating onLi(Co_(0.97)Mn_(0.03))O₂ compared with uncoated Li(Co_(0.97)Mn_(0.03))O₂and Al₂O₃ coating on Li(Co_(0.97)Mn_(0.03))O₂, according to anillustrative embodiment. The complex oxide ZnAl₂O₄ coating also enhancesthe energy retention, as shown in FIG. 16 by a less steeper slope thanthe Al₂O₃ coating. For example, after 30 cycles, the energy retentionbecomes about 0.97 for the complex oxide ZnAl₂O₄ coating, which ishigher than an energy retention of about 0.95 for the Al₂O₃ coating. Thecathode with the complex oxide ZnAl₂O₄ coating maintains higher energyretention up to 30 cycles as shown in FIG. 16 .

Lower calcination temperature (e.g., 400° C.) was also used to form thecomplex oxide coating. However, no improvement was observed in theelectrochemical performance, which may be attributed to the too lowcalcination temperature to promote the complex oxide formation on thecathode active compound particles.

FIG. 17 is a phase diagram of binary oxides Al₂O₃ and ZnO. (Bur.Standards J. Research, 8(2) 280 1932; R.P.413). Even though the phasediagram of binary oxides exhibits formation of the spinel phase(ZnAl₂O₄) occurs at high temperatures, more recent studies (seeElectrochimica Acta 115 (2014) 326-331) show that the spinel phase canform at much lower temperatures. The phase formation also depends on thesynthesis procedure and condition. e.g., the spinel phase was formed at900° C. by using a sol-gel synthetic method.

The coatings, powder, and cathode active materials can be used inbatteries as described herein. The materials can be used in electronicdevices. An electronic device herein can refer to any electronic deviceknown in the art, including a portable electronic device. For example,the electronic device can be a telephone, such as a cell phone, and aland-line phone, or any communication device, such as a smart phone,including, for example an iPhone®, an electronic email sending/receivingdevice. The electronic device can also be an entertainment device,including a portable DVD player, conventional DVD player, Blue-Ray diskplayer, video game console, music player, such as a portable musicplayer (e.g., iPod®), etc. The electronic device can be a part of adisplay, such as a digital display, a TV monitor, an electronic-bookreader, a portable web-browser (e.g., iPad®), watch (e.g., AppleWatch),or a computer monitor. The electronic device can also be a part of adevice that provides control, such as controlling the streaming ofimages, videos, sounds (e.g., Apple TV®), or it can be a remote controlfor an electronic device. Moreover, the electronic device can be a partof a computer or its accessories, such as the hard drive tower housingor casing, laptop housing, laptop keyboard, laptop track pad, desktopkeyboard, mouse, and speaker. The battery and battery packs can also beapplied to a device such as a watch or a clock. The components poweredby a battery or battery pack can include, but are not limited to,microprocessors, computer readable storage media, in-put and/or out-putdevices such as a keyboard, track pad, touch-screen, mouse, speaker, andthe like.

The foregoing description, for purposes of explanation, used specificnomenclature to provide a thorough understanding of the describedembodiments. However, it will be apparent to one skilled in the art thatthe specific details are not required in order to practice the describedembodiments. Thus, the foregoing descriptions of the specificembodiments described herein are presented for purposes of illustrationand description. They are not targeted to be exhaustive or to limit theembodiments to the precise forms disclosed. It will be apparent to oneof ordinary skill in the art that many modifications and variations arepossible in view of the above teachings.

We claim:
 1. A cathode active material comprising: a plurality ofcathode active compound particles; and a coating disposed over each ofthe cathode active compound particles; the coating comprising a mixtureof Al₂O₃ and ZrO₂ or a mixture of La₂O₃ and Al₂O₃; wherein if thecoating is a mixture of La₂O₃ and Al₂O₃, the coating comprises aluminumfrom 40 ppm to 300 ppm and lanthanum from 200 ppm to 2000 ppm, andwherein if the coating is a mixture of Al₂O₃ and ZrO₂, the coatingcomprises aluminum from 40 ppm Al to 300 ppm Al and from 1000 ppm to2000 ppm zirconium.
 2. The cathode active material of claim 1, whereinthe coating comprises a mixture of La₂O₃ and Al₂O₃ having a molar ratioof La to Al equal to 0.01 to 5.0.
 3. The cathode active material ofclaim 1, wherein the cathode active compound particles comprise acompound of Formula (X):Li_(α)Co_(1−x−y)M_(y)Mn_(x)O_(δ)  (X) wherein M is at least one elementselected from the group consisting of B, Na, Mg, Ti, Ca, V, Cr, Fe, Co,Ni, Cu, Zn, Al, Sc, Y, Ga, Zr, Ru, and Mo; 0.95≤α≤1.05; 0<x≤0.30;0≤y≤0.10; and 1.98≤δ≤2.04.
 4. The cathode active material of claim 3,wherein 0.95≤α<0.99.
 5. A cathode comprising the coated cathode activematerial of claim
 1. 6. A battery cell, comprising: an anode comprisingan anode current collector, the cathode according to claim 5; and aseparator disposed between the anode and the cathode.
 7. The batterycell of claim 6, wherein the battery cell has a discharge energy greaterthan or equal to 710 Wh/kg after 25 cycles.
 8. The battery cell of claim6, wherein the battery cell has a first-cycle energy retention of atleast 90% after 30 discharge cycles.
 9. The battery cell of claim 6,wherein the battery cell has a first-cycle energy retention of at least95% after 30 discharge cycles.